feat(reflect): QUIC-native NAT reflection ("STUN for QUIC") — Phase 1

Lets a client ask its registered relay "what IP:port do you see for
me?" over the existing TLS-authenticated signal channel, returning
the client's server-reflexive address as a SocketAddr. Replaces the
need for a classic STUN deployment and becomes the bootstrap step
for future P2P hole-punching: once both peers know their own reflex
addrs, they can advertise them in DirectCallOffer and attempt a
direct QUIC handshake to each other.

Wire protocol (wzp-proto):
- SignalMessage::Reflect — unit variant, client -> relay
- SignalMessage::ReflectResponse { observed_addr: String } — relay -> client
- JSON-serde, appended at end of enum: zero ordinal concerns,
  backward compat with pre-Phase-1 relays by construction (older
  relays log "unexpected message" and drop; newer clients time out
  cleanly within 1s).

Relay handler (wzp-relay/src/main.rs, signal loop):
- New match arm next to Ping reuses the already-bound `addr` from
  connection.remote_address() and replies with observed_addr as a
  string. debug!-level log on success, warn!-level on send failure.

Client side (desktop/src-tauri/src/lib.rs):
- SignalState gains pending_reflect: Option<oneshot::Sender<SocketAddr>>.
- get_reflected_address Tauri command installs the oneshot before
  sending Reflect and awaits it with a 1s timeout; cleans up on
  every exit path (send failure, timeout, parse error).
- recv loop's new ReflectResponse arm fires the pending sender or
  emits a debug log for unsolicited responses — never crashes the
  loop on malformed input.
- Integrated into invoke_handler! alongside the other signal
  commands.

UI (desktop/index.html + src/main.ts):
- New "Network" section in settings panel with a "Detect" button
  that displays the reflected address or a categorized warning
  ("register first" / "relay does not support reflection" / error).

Tests (crates/wzp-relay/tests/reflect.rs — 3 new, all passing):
- reflect_happy_path: client on loopback gets back 127.0.0.1:<its own port>
- reflect_two_clients_distinct_ports: two concurrent clients see
  their own distinct ports, proving per-connection remote_address
- reflect_old_relay_times_out: mock relay that ignores Reflect —
  client times out between 1000-1200ms and does not hang

Also pre-existing test bit-rot unrelated to this PR — fixed so the
full workspace `cargo test` goes green:
- handshake_integration tests in wzp-client, wzp-relay and
  featherchat_compat in wzp-crypto all missed the `alias` field
  addition to CallOffer and the 3-arg form of perform_handshake
  plus 4-tuple return of accept_handshake. Updated to the current
  API surface.

Results:
  cargo test --workspace --exclude wzp-android: 386 passed
  cargo check --workspace: clean
  cargo clippy: no new warnings in touched files

Verification excludes wzp-android because it's dead code on this
branch (Tauri mobile uses wzp-native instead) and can't link -llog
on macOS host — unchanged status quo.

PRD: .taskmaster/docs/prd_reflect_over_quic.txt
Tasks: 39-46 all completed

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -10,6 +10,8 @@ members = [
     "crates/wzp-client",
     "crates/wzp-web",
     "crates/wzp-android",
+    "crates/wzp-native",
+    "desktop/src-tauri",
 ]
 
 [workspace.package]
@@ -60,3 +62,29 @@ wzp-fec = { path = "crates/wzp-fec" }
 wzp-crypto = { path = "crates/wzp-crypto" }
 wzp-transport = { path = "crates/wzp-transport" }
 wzp-client = { path = "crates/wzp-client" }
+
+# Fast dev profile: optimized but with debug info and incremental compilation.
+# Use with: cargo run --profile dev-fast
+[profile.dev-fast]
+inherits = "dev"
+opt-level = 2
+
+# Optimize heavy compute deps even in debug builds —
+# real-time audio needs < 20ms per frame, impossible unoptimized.
+[profile.dev.package.nnnoiseless]
+opt-level = 3
+[profile.dev.package.opusic-sys]
+opt-level = 3
+[profile.dev.package.raptorq]
+opt-level = 3
+[profile.dev.package.wzp-codec]
+opt-level = 3
+[profile.dev.package.wzp-fec]
+opt-level = 3
+
+# Phase 0 (opus-DRED): removed the [patch.crates-io] audiopus_sys = { path =
+# "vendor/audiopus_sys" } block. That patch existed to fix a Windows clang-cl
+# SIMD compile bug in libopus 1.3.1. With the swap to opusic-sys (libopus
+# 1.5.2), the upstream SIMD gating was fixed and the vendor patch is
+# obsolete. The vendor/audiopus_sys directory itself should be deleted as
+# part of the same cleanup — see the commit that follows this Phase 0.

android/app/src/main/java/com/wzp/engine/SignalManager.kt

@@ -1,97 +0,0 @@
-package com.wzp.engine
-
-import org.json.JSONObject
-
-/**
- * Persistent signal connection for direct 1:1 calls.
- * Separate from WzpEngine — survives across calls.
- *
- * Lifecycle: connect() → [placeCall/answerCall] → destroy()
- */
-class SignalManager {
-
-    private var handle: Long = 0L
-
-    val isConnected: Boolean get() = handle != 0L
-
-    /**
-     * Connect to relay and register for direct calls.
-     * MUST be called from a thread with sufficient stack (8MB).
-     * Blocks briefly during QUIC connect + register, then returns.
-     */
-    fun connect(relay: String, seedHex: String): Boolean {
-        if (handle != 0L) return true // already connected
-        handle = nativeSignalConnect(relay, seedHex)
-        return handle != 0L
-    }
-
-    /** Get current signal state as parsed object. Non-blocking. */
-    fun getState(): SignalState {
-        if (handle == 0L) return SignalState()
-        val json = nativeSignalGetState(handle) ?: return SignalState()
-        return try {
-            val obj = JSONObject(json)
-            SignalState(
-                status = obj.optString("status", "idle"),
-                fingerprint = obj.optString("fingerprint", ""),
-                incomingCallId = if (obj.isNull("incoming_call_id")) null else obj.optString("incoming_call_id"),
-                incomingCallerFp = if (obj.isNull("incoming_caller_fp")) null else obj.optString("incoming_caller_fp"),
-                incomingCallerAlias = if (obj.isNull("incoming_caller_alias")) null else obj.optString("incoming_caller_alias"),
-                callSetupRelay = if (obj.isNull("call_setup_relay")) null else obj.optString("call_setup_relay"),
-                callSetupRoom = if (obj.isNull("call_setup_room")) null else obj.optString("call_setup_room"),
-                callSetupId = if (obj.isNull("call_setup_id")) null else obj.optString("call_setup_id"),
-            )
-        } catch (e: Exception) {
-            SignalState()
-        }
-    }
-
-    /** Place a direct call to a target fingerprint. */
-    fun placeCall(targetFp: String): Int {
-        if (handle == 0L) return -1
-        return nativeSignalPlaceCall(handle, targetFp)
-    }
-
-    /** Answer an incoming call. mode: 0=Reject, 1=AcceptTrusted, 2=AcceptGeneric */
-    fun answerCall(callId: String, mode: Int = 2): Int {
-        if (handle == 0L) return -1
-        return nativeSignalAnswerCall(handle, callId, mode)
-    }
-
-    /** Send hangup signal. */
-    fun hangup() {
-        if (handle != 0L) nativeSignalHangup(handle)
-    }
-
-    /** Destroy the signal manager. */
-    fun destroy() {
-        if (handle != 0L) {
-            nativeSignalDestroy(handle)
-            handle = 0L
-        }
-    }
-
-    // JNI native methods
-    private external fun nativeSignalConnect(relay: String, seed: String): Long
-    private external fun nativeSignalGetState(handle: Long): String?
-    private external fun nativeSignalPlaceCall(handle: Long, targetFp: String): Int
-    private external fun nativeSignalAnswerCall(handle: Long, callId: String, mode: Int): Int
-    private external fun nativeSignalHangup(handle: Long)
-    private external fun nativeSignalDestroy(handle: Long)
-
-    companion object {
-        init { System.loadLibrary("wzp_android") }
-    }
-}
-
-/** Signal connection state. */
-data class SignalState(
-    val status: String = "idle",
-    val fingerprint: String = "",
-    val incomingCallId: String? = null,
-    val incomingCallerFp: String? = null,
-    val incomingCallerAlias: String? = null,
-    val callSetupRelay: String? = null,
-    val callSetupRoom: String? = null,
-    val callSetupId: String? = null,
-)

android/app/src/main/java/com/wzp/engine/WzpEngine.kt

@@ -159,18 +159,6 @@ class WzpEngine(private val callback: WzpCallback) {
     private external fun nativeWriteAudioDirect(handle: Long, buffer: java.nio.ByteBuffer, sampleCount: Int): Int
     private external fun nativeReadAudioDirect(handle: Long, buffer: java.nio.ByteBuffer, maxSamples: Int): Int
     private external fun nativeDestroy(handle: Long)
-
-    companion object {
-        init { System.loadLibrary("wzp_android") }
-
-        /** Get the identity fingerprint for a seed hex. No engine needed. */
-        @JvmStatic
-        private external fun nativeGetFingerprint(seedHex: String): String?
-
-        /** Compute the full identity fingerprint (xxxx:xxxx:...) from a seed hex string. */
-        @JvmStatic
-        fun getFingerprint(seedHex: String): String = nativeGetFingerprint(seedHex) ?: ""
-    }
     private external fun nativePingRelay(handle: Long, relay: String): String?
     private external fun nativeStartSignaling(handle: Long, relay: String, seed: String, token: String, alias: String): Int
     private external fun nativePlaceCall(handle: Long, targetFp: String): Int
@@ -220,6 +208,11 @@ class WzpEngine(private val callback: WzpCallback) {
         return nativeAnswerCall(nativeHandle, callId, mode)
     }
 
+    companion object {
+        init {
+            System.loadLibrary("wzp_android")
+        }
+    }
 }
 
 /** Integer constants matching the Rust [CallState] enum ordinals. */

android/app/src/main/java/com/wzp/ui/call/CallViewModel.kt

@@ -141,9 +141,9 @@ class CallViewModel : ViewModel(), WzpCallback {
     private val _targetFingerprint = MutableStateFlow("")
     val targetFingerprint: StateFlow<String> = _targetFingerprint.asStateFlow()
 
-    /** Signal state string: "idle", "registered", "ringing", "incoming", "setup" */
+    /** Signal connection state: 0=idle, 5=registered, 6=ringing, 7=incoming */
-    private val _signalState = MutableStateFlow("idle")
+    private val _signalState = MutableStateFlow(0)
-    val signalState: StateFlow<String> = _signalState.asStateFlow()
+    val signalState: StateFlow<Int> = _signalState.asStateFlow()
 
     /** Incoming call info */
     private val _incomingCallId = MutableStateFlow<String?>(null)
@@ -155,80 +155,32 @@ class CallViewModel : ViewModel(), WzpCallback {
     private val _incomingCallerAlias = MutableStateFlow<String?>(null)
     val incomingCallerAlias: StateFlow<String?> = _incomingCallerAlias.asStateFlow()
 
-    /** Separate signal manager (persistent, survives calls) */
-    private var signalManager: com.wzp.engine.SignalManager? = null
-    private var signalPollJob: Job? = null
-
     fun setCallMode(mode: Int) { _callMode.value = mode }
     fun setTargetFingerprint(fp: String) { _targetFingerprint.value = fp }
 
     /** Register on relay for direct calls */
     fun registerForCalls() {
+        if (engine == null) {
+            engine = WzpEngine(this).also { it.init() }
+        }
         val serverIdx = _selectedServer.value
         val serverList = _servers.value
         if (serverIdx >= serverList.size) return
 
         val relay = serverList[serverIdx].address
-        var seed = _seedHex.value
+        val seed = _seedHex.value
-        // Generate seed if empty (fresh install or cleared storage)
+        val alias = _alias.value
-        if (seed.isEmpty()) {
-            val newSeed = ByteArray(32).also { java.security.SecureRandom().nextBytes(it) }
-            seed = newSeed.joinToString("") { "%02x".format(it) }
-            _seedHex.value = seed
-            settings?.saveSeedHex(seed)
-            Log.i(TAG, "generated new identity seed")
-        }
-        val resolvedRelay = resolveToIp(relay) ?: relay
 
-        // nativeSignalConnect has JNI overhead — must be on a thread with enough stack.
+        viewModelScope.launch(Dispatchers.IO) {
-        // Dispatchers.IO threads overflow. Use explicit Java Thread.
+            val resolvedRelay = resolveToIp(relay) ?: relay
-        Thread(null, {
+            val result = engine?.startSignaling(resolvedRelay, seed, "", alias)
-            try {
+            if (result == 0) {
-                val mgr = com.wzp.engine.SignalManager()
+                _signalState.value = 5 // Registered
-                val ok = mgr.connect(resolvedRelay, seed)
+                startStatsPolling()
-                viewModelScope.launch {
-                    if (ok) {
-                        signalManager = mgr
-                        startSignalPolling()
             } else {
                 _errorMessage.value = "Failed to register on relay"
             }
         }
-            } catch (e: Exception) {
-                viewModelScope.launch {
-                    _errorMessage.value = "Register error: ${e.message}"
-                }
-            }
-        }, "wzp-signal-init", 8 * 1024 * 1024).start()
-    }
-
-    /** Poll signal manager state every 500ms */
-    private fun startSignalPolling() {
-        signalPollJob?.cancel()
-        signalPollJob = viewModelScope.launch {
-            while (isActive) {
-                val mgr = signalManager
-                if (mgr != null && mgr.isConnected) {
-                    val state = mgr.getState()
-                    _signalState.value = state.status
-                    _incomingCallId.value = state.incomingCallId
-                    _incomingCallerFp.value = state.incomingCallerFp
-                    _incomingCallerAlias.value = state.incomingCallerAlias
-
-                    // Auto-connect to media room when call is set up
-                    if (state.status == "setup" && state.callSetupRelay != null && state.callSetupRoom != null) {
-                        Log.i(TAG, "CallSetup: connecting to ${state.callSetupRelay} room ${state.callSetupRoom}")
-                        startCallInternal(state.callSetupRelay, state.callSetupRoom)
-                    }
-                }
-                delay(500L)
-            }
-        }
-    }
-
-    private fun stopSignalPolling() {
-        signalPollJob?.cancel()
-        signalPollJob = null
     }
 
     /** Place a direct call to the target fingerprint */
@@ -238,28 +190,24 @@ class CallViewModel : ViewModel(), WzpCallback {
             _errorMessage.value = "Enter a fingerprint to call"
             return
         }
-        signalManager?.placeCall(target)
+        engine?.placeCall(target)
+        _signalState.value = 6 // Ringing
     }
 
     /** Answer an incoming direct call */
     fun answerIncomingCall(mode: Int = 2) {
         val callId = _incomingCallId.value ?: return
-        signalManager?.answerCall(callId, mode)
+        engine?.answerCall(callId, mode)
     }
 
     /** Reject an incoming direct call */
     fun rejectIncomingCall() {
         val callId = _incomingCallId.value ?: return
-        signalManager?.answerCall(callId, 0)
+        engine?.answerCall(callId, 0) // 0 = Reject
-    }
+        _signalState.value = 5 // Back to registered
-
+        _incomingCallId.value = null
-    /** Hang up direct call — media ends, signal stays alive */
+        _incomingCallerFp.value = null
-    fun hangupDirectCall() {
+        _incomingCallerAlias.value = null
-        signalManager?.hangup()
-        engine?.stopCall()
-        engine?.destroy()
-        engine = null
-        engineInitialized = false
     }
 
     companion object {
@@ -737,10 +685,30 @@ class CallViewModel : ViewModel(), WzpCallback {
                         val s = CallStats.fromJson(json)
                         lastCallDuration = s.durationSecs
                         _stats.value = s
-                        // Only update callState from media engine stats (not signal)
                         if (s.state != 0) {
                             _callState.value = s.state
                         }
+                        // Track signal state changes for direct calling
+                        if (s.state in 5..7) {
+                            _signalState.value = s.state
+                        }
+                        // Incoming call detection
+                        if (s.state == 7) { // IncomingCall
+                            _incomingCallId.value = s.incomingCallId
+                            _incomingCallerFp.value = s.incomingCallerFp
+                            _incomingCallerAlias.value = s.incomingCallerAlias
+                        }
+                        // CallSetup: auto-connect to media room
+                        if (s.state == 1 && s.incomingCallId != null && s.incomingCallId.contains("|")) {
+                            // Format: "relay_addr|room_name"
+                            val parts = s.incomingCallId.split("|", limit = 2)
+                            if (parts.size == 2) {
+                                val mediaRelay = parts[0]
+                                val mediaRoom = parts[1]
+                                Log.i(TAG, "CallSetup: connecting to $mediaRelay room $mediaRoom")
+                                startCallInternal(mediaRelay, mediaRoom)
+                            }
+                        }
                         if (s.state == 2 && !audioStarted) {
                             startAudio()
                         }

android/app/src/main/java/com/wzp/ui/call/InCallScreen.kt

@@ -165,7 +165,7 @@ fun InCallScreen(
                     color = Color.White
                 )
                 Text(
-                    text = "ENCRYPTED VOICE  \u2022  direct-call-v1",
+                    text = "ENCRYPTED VOICE",
                     style = MaterialTheme.typography.labelSmall.copy(letterSpacing = 3.sp),
                     color = TextDim
                 )
@@ -219,7 +219,7 @@ fun InCallScreen(
 
                 // Mode toggle: Room vs Direct Call
                 val callMode by viewModel.callMode.collectAsState()
-                val signalState by viewModel.signalState.collectAsState()  // "idle"/"registered"/"ringing"/etc
+                val signalState by viewModel.signalState.collectAsState()
                 val targetFp by viewModel.targetFingerprint.collectAsState()
                 val incomingCallId by viewModel.incomingCallId.collectAsState()
                 val incomingCallerFp by viewModel.incomingCallerFp.collectAsState()
@@ -309,7 +309,7 @@ fun InCallScreen(
                     }
                 } else {
                     // ── Direct call mode ──
-                    if (signalState == "idle") {
+                    if (signalState < 5) {
                         // Not registered yet
                         SectionLabel("ALIAS")
                         OutlinedTextField(
@@ -333,7 +333,7 @@ fun InCallScreen(
                                 color = Color.White
                             )
                         }
-                    } else if (signalState == "registered" || signalState == "incoming") {
+                    } else if (signalState == 5) {
                         // Registered — show dial pad
                         Text(
                             "\u2705 Registered — waiting for calls",
@@ -403,7 +403,8 @@ fun InCallScreen(
                                 color = Color.White
                             )
                         }
-                    } else if (signalState == "ringing") {
+                    } else if (signalState == 6) {
+                        // Ringing
                         Text(
                             "\uD83D\uDD14 Ringing...",
                             color = Yellow,
@@ -411,10 +412,11 @@ fun InCallScreen(
                             textAlign = TextAlign.Center,
                             modifier = Modifier.fillMaxWidth()
                         )
-                    } else if (signalState == "setup") {
+                    } else if (signalState == 7) {
+                        // Incoming call (state 7 also handled above in registered view)
                         Text(
-                            "Connecting to call...",
+                            "\uD83D\uDCDE Incoming call...",
-                            color = Accent,
+                            color = Green,
                             style = MaterialTheme.typography.titleMedium,
                             textAlign = TextAlign.Center,
                             modifier = Modifier.fillMaxWidth()
@@ -429,16 +431,14 @@ fun InCallScreen(
 
                 Spacer(modifier = Modifier.height(20.dp))
 
-                // Identity — compute real fingerprint from seed
+                // Identity
-                val fullFp = remember(seedHex) {
+                val fp = if (seedHex.length >= 16) seedHex.take(16) else ""
-                    if (seedHex.length >= 64) com.wzp.engine.WzpEngine.getFingerprint(seedHex) else ""
-                }
                 Row(verticalAlignment = Alignment.CenterVertically) {
-                    if (fullFp.isNotEmpty()) {
+                    if (fp.isNotEmpty()) {
-                        Identicon(fingerprint = fullFp, size = 28.dp)
+                        Identicon(fingerprint = seedHex, size = 28.dp)
                         Spacer(modifier = Modifier.width(8.dp))
                         CopyableFingerprint(
-                            fingerprint = fullFp,
+                            fingerprint = fp.chunked(4).joinToString(":"),
                             style = MaterialTheme.typography.bodySmall.copy(fontFamily = FontFamily.Monospace),
                             color = TextDim
                         )

crates/wzp-android/src/engine.rs

@@ -203,6 +203,7 @@ impl WzpEngine {
     /// Returns JSON `{"rtt_ms":N,"server_fingerprint":"hex"}` or error.
     pub fn ping_relay(&self, address: &str) -> Result<String, anyhow::Error> {
         let addr: SocketAddr = address.parse()?;
+        let _ = rustls::crypto::ring::default_provider().install_default();
 
         let rt = tokio::runtime::Builder::new_current_thread()
             .enable_all()
@@ -246,7 +247,154 @@ impl WzpEngine {
     }
 
     /// Start persistent signaling connection for direct calls.
-    // Signal methods (start_signaling, place_call, answer_call) moved to signal_mgr.rs
+    /// Spawns a background task that maintains the `_signal` connection.
+    pub fn start_signaling(
+        &mut self,
+        relay_addr: &str,
+        seed_hex: &str,
+        token: Option<&str>,
+        alias: Option<&str>,
+    ) -> Result<(), anyhow::Error> {
+        use wzp_proto::{MediaTransport, SignalMessage};
+
+        let addr: SocketAddr = relay_addr.parse()?;
+        let seed = if seed_hex.is_empty() {
+            wzp_crypto::Seed::generate()
+        } else {
+            wzp_crypto::Seed::from_hex(seed_hex).map_err(|e| anyhow::anyhow!(e))?
+        };
+        let identity = seed.derive_identity();
+        let pub_id = identity.public_identity();
+        let identity_pub = *pub_id.signing.as_bytes();
+        let fp = pub_id.fingerprint.to_string();
+        let token = token.map(|s| s.to_string());
+        let alias = alias.map(|s| s.to_string());
+        let state = self.state.clone();
+        let seed_bytes = seed.0;
+
+        info!(fingerprint = %fp, relay = %addr, "starting signaling");
+
+        // Create runtime for signaling (separate from call runtime)
+        let rt = tokio::runtime::Builder::new_multi_thread()
+            .worker_threads(1)
+            .enable_all()
+            .build()?;
+
+        let signal_state = state.clone();
+        rt.spawn(async move {
+            let _ = rustls::crypto::ring::default_provider().install_default();
+            let bind: SocketAddr = "0.0.0.0:0".parse().unwrap();
+            let endpoint = match wzp_transport::create_endpoint(bind, None) {
+                Ok(e) => e,
+                Err(e) => { error!("signal endpoint: {e}"); return; }
+            };
+            let client_cfg = wzp_transport::client_config();
+            let conn = match wzp_transport::connect(&endpoint, addr, "_signal", client_cfg).await {
+                Ok(c) => c,
+                Err(e) => { error!("signal connect: {e}"); return; }
+            };
+            let transport = std::sync::Arc::new(wzp_transport::QuinnTransport::new(conn));
+
+            // Auth if token provided
+            if let Some(ref tok) = token {
+                let _ = transport.send_signal(&SignalMessage::AuthToken { token: tok.clone() }).await;
+            }
+
+            // Register presence
+            let _ = transport.send_signal(&SignalMessage::RegisterPresence {
+                identity_pub,
+                signature: vec![],
+                alias: alias.clone(),
+            }).await;
+
+            // Wait for ack
+            match transport.recv_signal().await {
+                Ok(Some(SignalMessage::RegisterPresenceAck { success: true, .. })) => {
+                    info!(fingerprint = %fp, "signal: registered");
+                    let mut stats = signal_state.stats.lock().unwrap();
+                    stats.state = crate::stats::CallState::Registered;
+                }
+                other => {
+                    error!("signal registration failed: {other:?}");
+                    return;
+                }
+            }
+
+            // Signal recv loop
+            loop {
+                if !signal_state.running.load(Ordering::Relaxed) {
+                    break;
+                }
+                match transport.recv_signal().await {
+                    Ok(Some(SignalMessage::CallRinging { call_id })) => {
+                        info!(call_id = %call_id, "signal: ringing");
+                        let mut stats = signal_state.stats.lock().unwrap();
+                        stats.state = crate::stats::CallState::Ringing;
+                    }
+                    Ok(Some(SignalMessage::DirectCallOffer { caller_fingerprint, caller_alias, call_id, .. })) => {
+                        info!(from = %caller_fingerprint, call_id = %call_id, "signal: incoming call");
+                        let mut stats = signal_state.stats.lock().unwrap();
+                        stats.state = crate::stats::CallState::IncomingCall;
+                        stats.incoming_call_id = Some(call_id);
+                        stats.incoming_caller_fp = Some(caller_fingerprint);
+                        stats.incoming_caller_alias = caller_alias;
+                    }
+                    Ok(Some(SignalMessage::DirectCallAnswer { call_id, accept_mode, .. })) => {
+                        info!(call_id = %call_id, mode = ?accept_mode, "signal: call answered");
+                    }
+                    Ok(Some(SignalMessage::CallSetup { call_id, room, relay_addr })) => {
+                        info!(call_id = %call_id, room = %room, relay = %relay_addr, "signal: call setup");
+                        // Connect to media room via the existing start_call mechanism
+                        // Store the room info so Kotlin can call startCall with it
+                        let mut stats = signal_state.stats.lock().unwrap();
+                        stats.state = crate::stats::CallState::Connecting;
+                        // Store call setup info for Kotlin to pick up
+                        stats.incoming_call_id = Some(format!("{relay_addr}|{room}"));
+                    }
+                    Ok(Some(SignalMessage::Hangup { reason })) => {
+                        info!(reason = ?reason, "signal: call ended by remote");
+                        let mut stats = signal_state.stats.lock().unwrap();
+                        stats.state = crate::stats::CallState::Closed;
+                        stats.incoming_call_id = None;
+                        stats.incoming_caller_fp = None;
+                        stats.incoming_caller_alias = None;
+                    }
+                    Ok(Some(_)) => {}
+                    Ok(None) => {
+                        info!("signal: connection closed");
+                        break;
+                    }
+                    Err(e) => {
+                        error!("signal recv error: {e}");
+                        break;
+                    }
+                }
+            }
+
+            let mut stats = signal_state.stats.lock().unwrap();
+            stats.state = crate::stats::CallState::Closed;
+        });
+
+        self.tokio_runtime = Some(rt);
+        Ok(())
+    }
+
+    /// Place a direct call to a target fingerprint via the signal connection.
+    pub fn place_call(&self, target_fingerprint: &str) -> Result<(), anyhow::Error> {
+        let _ = self.state.command_tx.send(EngineCommand::PlaceCall {
+            target_fingerprint: target_fingerprint.to_string(),
+        });
+        Ok(())
+    }
+
+    /// Answer an incoming direct call.
+    pub fn answer_call(&self, call_id: &str, mode: wzp_proto::CallAcceptMode) -> Result<(), anyhow::Error> {
+        let _ = self.state.command_tx.send(EngineCommand::AnswerCall {
+            call_id: call_id.to_string(),
+            accept_mode: mode,
+        });
+        Ok(())
+    }
 
     pub fn set_mute(&self, muted: bool) {
         self.state.muted.store(muted, Ordering::Relaxed);
@@ -310,6 +458,7 @@ async fn run_call(
     alias: Option<&str>,
     state: Arc<EngineState>,
 ) -> Result<(), anyhow::Error> {
+    let _ = rustls::crypto::ring::default_provider().install_default();
 
     let bind_addr: SocketAddr = "0.0.0.0:0".parse().unwrap();
     let endpoint = wzp_transport::create_endpoint(bind_addr, None)?;

crates/wzp-android/src/jni_bridge.rs

@@ -77,9 +77,6 @@ pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeInit(
 ) -> jlong {
     let result = panic::catch_unwind(|| {
         init_logging();
-        // Install rustls crypto provider ONCE on the main thread.
-        // Must not be called per-thread — conflicts with Android's system libcrypto.so TLS keys.
-        let _ = rustls::crypto::ring::default_provider().install_default();
         let handle = Box::new(EngineHandle {
             engine: WzpEngine::new(),
         });
@@ -363,149 +360,88 @@ pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativePingRelay<'a>(
         .unwrap_or(JObject::null().into_raw())
 }
 
-/// Get the identity fingerprint for a seed hex string.
-/// Returns the full fingerprint (xxxx:xxxx:...) or empty string on error.
-#[unsafe(no_mangle)]
-pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeGetFingerprint<'a>(
-    mut env: JNIEnv<'a>,
-    _class: JClass,
-    seed_hex_j: JString,
-) -> jstring {
-    let seed_hex: String = env.get_string(&seed_hex_j).map(|s| s.into()).unwrap_or_default();
-    let fp = if seed_hex.is_empty() {
-        String::new()
-    } else {
-        match wzp_crypto::Seed::from_hex(&seed_hex) {
-            Ok(seed) => {
-                let id = seed.derive_identity();
-                id.public_identity().fingerprint.to_string()
-            }
-            Err(_) => String::new(),
-        }
-    };
-    env.new_string(&fp)
-        .map(|s| s.into_raw())
-        .unwrap_or(JObject::null().into_raw())
-}
-
 // ── Direct calling JNI functions ──
 
-// ── SignalManager JNI functions ──
+/// Start persistent signaling connection to relay for direct calls.
-
+/// Returns 0 on success, -1 on error.
-/// Opaque handle for SignalManager (separate from EngineHandle).
-struct SignalHandle {
-    mgr: crate::signal_mgr::SignalManager,
-}
-
-unsafe fn signal_ref(handle: jlong) -> &'static SignalHandle {
-    unsafe { &*(handle as *const SignalHandle) }
-}
-
-/// Connect to relay for signaling. Returns handle (jlong) or 0 on error.
-/// Blocks up to 10s waiting for the internal signal thread to connect.
 #[unsafe(no_mangle)]
-pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalConnect<'a>(
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeStartSignaling<'a>(
-    mut env: JNIEnv<'a>,
-    _class: JClass,
-    relay_j: JString,
-    seed_j: JString,
-) -> jlong {
-    info!("nativeSignalConnect: entered");
-    let relay: String = env.get_string(&relay_j).map(|s| s.into()).unwrap_or_default();
-    let seed: String = env.get_string(&seed_j).map(|s| s.into()).unwrap_or_default();
-    info!(relay = %relay, seed_len = seed.len(), "nativeSignalConnect: parsed strings");
-
-    // start() spawns an internal thread (connect+register+recv, ONE runtime, never dropped).
-    // Blocks up to 10s waiting for the connect+register to complete.
-    match crate::signal_mgr::SignalManager::start(&relay, &seed) {
-        Ok(mgr) => {
-            let handle = Box::new(SignalHandle { mgr });
-            Box::into_raw(handle) as jlong
-        }
-        Err(e) => {
-            error!("signal connect failed: {e}");
-            0
-        }
-    }
-}
-
-/// Get signal state as JSON string.
-#[unsafe(no_mangle)]
-pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalGetState<'a>(
     mut env: JNIEnv<'a>,
     _class: JClass,
     handle: jlong,
-) -> jstring {
+    relay_addr_j: JString,
-    if handle == 0 { return JObject::null().into_raw(); }
+    seed_hex_j: JString,
-    let h = signal_ref(handle);
+    token_j: JString,
-    let json = h.mgr.get_state_json();
+    alias_j: JString,
-    env.new_string(&json)
-        .map(|s| s.into_raw())
-        .unwrap_or(JObject::null().into_raw())
-}
-
-/// Place a direct call.
-#[unsafe(no_mangle)]
-pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalPlaceCall<'a>(
-    mut env: JNIEnv<'a>,
-    _class: JClass,
-    handle: jlong,
-    target_j: JString,
 ) -> jint {
-    if handle == 0 { return -1; }
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
-    let h = signal_ref(handle);
+        let h = unsafe { handle_ref(handle) };
-    let target: String = env.get_string(&target_j).map(|s| s.into()).unwrap_or_default();
+        let relay_addr: String = env.get_string(&relay_addr_j).map(|s| s.into()).unwrap_or_default();
-    match h.mgr.place_call(&target) {
+        let seed_hex: String = env.get_string(&seed_hex_j).map(|s| s.into()).unwrap_or_default();
-        Ok(()) => 0,
+        let token: String = env.get_string(&token_j).map(|s| s.into()).unwrap_or_default();
-        Err(e) => { error!("place_call: {e}"); -1 }
+        let alias: String = env.get_string(&alias_j).map(|s| s.into()).unwrap_or_default();
+
+        h.engine.start_signaling(
+            &relay_addr,
+            &seed_hex,
+            if token.is_empty() { None } else { Some(&token) },
+            if alias.is_empty() { None } else { Some(&alias) },
+        )
+    }));
+
+    match result {
+        Ok(Ok(())) => 0,
+        Ok(Err(e)) => { error!("start_signaling failed: {e}"); -1 }
+        Err(_) => { error!("start_signaling panicked"); -1 }
     }
 }
 
-/// Answer an incoming call.
+/// Place a direct call to a target fingerprint.
+/// Returns 0 on success, -1 on error.
 #[unsafe(no_mangle)]
-pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalAnswerCall<'a>(
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativePlaceCall<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    handle: jlong,
+    target_fp_j: JString,
+) -> jint {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let target: String = env.get_string(&target_fp_j).map(|s| s.into()).unwrap_or_default();
+        h.engine.place_call(&target)
+    }));
+
+    match result {
+        Ok(Ok(())) => 0,
+        Ok(Err(e)) => { error!("place_call failed: {e}"); -1 }
+        Err(_) => { error!("place_call panicked"); -1 }
+    }
+}
+
+/// Answer an incoming direct call.
+/// mode: 0=Reject, 1=AcceptTrusted, 2=AcceptGeneric
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeAnswerCall<'a>(
     mut env: JNIEnv<'a>,
     _class: JClass,
     handle: jlong,
     call_id_j: JString,
     mode: jint,
 ) -> jint {
-    if handle == 0 { return -1; }
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
-    let h = signal_ref(handle);
+        let h = unsafe { handle_ref(handle) };
         let call_id: String = env.get_string(&call_id_j).map(|s| s.into()).unwrap_or_default();
         let accept_mode = match mode {
             0 => wzp_proto::CallAcceptMode::Reject,
             1 => wzp_proto::CallAcceptMode::AcceptTrusted,
             _ => wzp_proto::CallAcceptMode::AcceptGeneric,
         };
-    match h.mgr.answer_call(&call_id, accept_mode) {
+        h.engine.answer_call(&call_id, accept_mode)
-        Ok(()) => 0,
+    }));
-        Err(e) => { error!("answer_call: {e}"); -1 }
+
+    match result {
+        Ok(Ok(())) => 0,
+        Ok(Err(e)) => { error!("answer_call failed: {e}"); -1 }
+        Err(_) => { error!("answer_call panicked"); -1 }
     }
 }
-
-/// Send hangup signal.
-#[unsafe(no_mangle)]
-pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalHangup(
-    _env: JNIEnv,
-    _class: JClass,
-    handle: jlong,
-) {
-    if handle == 0 { return; }
-    let h = signal_ref(handle);
-    h.mgr.hangup();
-}
-
-/// Destroy the signal manager and free resources.
-#[unsafe(no_mangle)]
-pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalDestroy(
-    _env: JNIEnv,
-    _class: JClass,
-    handle: jlong,
-) {
-    if handle == 0 { return; }
-    let h = signal_ref(handle);
-    h.mgr.stop();
-    // Reclaim the Box
-    let _ = unsafe { Box::from_raw(handle as *mut SignalHandle) };
-}

crates/wzp-android/src/lib.rs

@@ -8,12 +8,24 @@
 //!
 //! On non-Android targets, the Oboe C++ layer compiles as a stub,
 //! allowing `cargo check` and unit tests on the host.
+//!
+//! ## Status
+//!
+//! **Dead code as of the Tauri mobile rewrite.** The legacy Kotlin+JNI
+//! Android app that consumed this crate was replaced by a Tauri 2.x
+//! Mobile app (see `desktop/src-tauri/src/engine.rs` for the live
+//! Android audio recv path and `crates/wzp-native/` for the Oboe
+//! bridge). We keep this crate in the workspace for reference and to
+//! preserve the commit history, but it is not built by any shipping
+//! target. Allow the accumulated leftover warnings so CI/workspace
+//! checks stay clean — any real cleanup should happen as part of
+//! removing the crate entirely, not piecemeal.
+#![allow(dead_code, unused_imports, unused_variables, unused_mut)]
 
 pub mod audio_android;
 pub mod audio_ring;
 pub mod commands;
 pub mod engine;
 pub mod pipeline;
-pub mod signal_mgr;
 pub mod stats;
 pub mod jni_bridge;

crates/wzp-android/src/signal_mgr.rs

@@ -1,288 +0,0 @@
-//! Persistent signal connection manager for direct 1:1 calls.
-//!
-//! Separate from the media engine — survives across calls.
-//! Connects to relay via `_signal` SNI, registers presence,
-//! and handles call signaling (offer/answer/setup/hangup).
-
-use std::net::SocketAddr;
-use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::{Arc, Mutex};
-
-use tracing::{error, info, warn};
-use wzp_proto::{MediaTransport, SignalMessage};
-
-/// Signal connection status.
-#[derive(Clone, Debug, Default, serde::Serialize)]
-pub struct SignalState {
-    pub status: String, // "idle", "registered", "ringing", "incoming", "setup"
-    pub fingerprint: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub incoming_call_id: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub incoming_caller_fp: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub incoming_caller_alias: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub call_setup_relay: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub call_setup_room: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub call_setup_id: Option<String>,
-}
-
-/// Manages a persistent `_signal` QUIC connection to a relay.
-pub struct SignalManager {
-    transport: Arc<wzp_transport::QuinnTransport>,
-    state: Arc<Mutex<SignalState>>,
-    running: Arc<AtomicBool>,
-}
-
-impl SignalManager {
-    /// Create SignalManager and start connect+register+recv on a background thread.
-    /// Returns immediately. The internal thread runs forever.
-    /// CRITICAL: tokio runtime must never be dropped on Android (libcrypto TLS conflict).
-    pub fn start(relay_addr: &str, seed_hex: &str) -> Result<Self, anyhow::Error> {
-        let addr: SocketAddr = relay_addr.parse()?;
-        let seed = if seed_hex.is_empty() {
-            wzp_crypto::Seed::generate()
-        } else {
-            wzp_crypto::Seed::from_hex(seed_hex).map_err(|e| anyhow::anyhow!(e))?
-        };
-        let identity = seed.derive_identity();
-        let pub_id = identity.public_identity();
-        let identity_pub = *pub_id.signing.as_bytes();
-        let fp = pub_id.fingerprint.to_string();
-
-        let state = Arc::new(Mutex::new(SignalState {
-            status: "connecting".into(),
-            fingerprint: fp.clone(),
-            ..Default::default()
-        }));
-        let running = Arc::new(AtomicBool::new(true));
-
-        // Channel to receive transport after connect succeeds
-        let (transport_tx, transport_rx) = std::sync::mpsc::channel();
-
-        let bg_state = Arc::clone(&state);
-        let bg_running = Arc::clone(&running);
-        let ret_state = Arc::clone(&state);
-        let ret_running = Arc::clone(&running);
-
-        // ONE thread, ONE runtime, NEVER dropped.
-        // Connect + register + recv loop all happen here.
-        std::thread::Builder::new()
-            .name("wzp-signal".into())
-            .stack_size(4 * 1024 * 1024)
-            .spawn(move || {
-                let rt = tokio::runtime::Builder::new_current_thread()
-                    .enable_all()
-                    .build()
-                    .expect("tokio runtime");
-
-                rt.block_on(async move {
-                    info!(fingerprint = %fp, relay = %addr, "signal: connecting");
-
-                    let bind: SocketAddr = "0.0.0.0:0".parse().unwrap();
-                    let endpoint = match wzp_transport::create_endpoint(bind, None) {
-                        Ok(e) => e,
-                        Err(e) => {
-                            error!("signal endpoint: {e}");
-                            bg_state.lock().unwrap().status = "idle".into();
-                            return;
-                        }
-                    };
-                    let client_cfg = wzp_transport::client_config();
-                    let conn = match wzp_transport::connect(&endpoint, addr, "_signal", client_cfg).await {
-                        Ok(c) => c,
-                        Err(e) => {
-                            error!("signal connect: {e}");
-                            bg_state.lock().unwrap().status = "idle".into();
-                            return;
-                        }
-                    };
-                    let transport = Arc::new(wzp_transport::QuinnTransport::new(conn));
-
-                    // Register
-                    if let Err(e) = transport.send_signal(&SignalMessage::RegisterPresence {
-                        identity_pub, signature: vec![], alias: None,
-                    }).await {
-                        error!("signal register: {e}");
-                        bg_state.lock().unwrap().status = "idle".into();
-                        return;
-                    }
-
-                    match transport.recv_signal().await {
-                        Ok(Some(SignalMessage::RegisterPresenceAck { success: true, .. })) => {
-                            info!(fingerprint = %fp, "signal: registered");
-                            bg_state.lock().unwrap().status = "registered".into();
-                            // Send transport to caller
-                            let _ = transport_tx.send(transport.clone());
-                        }
-                        other => {
-                            error!("signal registration failed: {other:?}");
-                            bg_state.lock().unwrap().status = "idle".into();
-                            return;
-                        }
-                    }
-
-                    // Recv loop — runs forever
-            loop {
-                if !running.load(Ordering::Relaxed) { break; }
-
-                match transport.recv_signal().await {
-                    Ok(Some(SignalMessage::CallRinging { call_id })) => {
-                        info!(call_id = %call_id, "signal: ringing");
-                        let mut s = state.lock().unwrap();
-                        s.status = "ringing".into();
-                    }
-                    Ok(Some(SignalMessage::DirectCallOffer { caller_fingerprint, caller_alias, call_id, .. })) => {
-                        info!(from = %caller_fingerprint, call_id = %call_id, "signal: incoming call");
-                        let mut s = state.lock().unwrap();
-                        s.status = "incoming".into();
-                        s.incoming_call_id = Some(call_id);
-                        s.incoming_caller_fp = Some(caller_fingerprint);
-                        s.incoming_caller_alias = caller_alias;
-                    }
-                    Ok(Some(SignalMessage::DirectCallAnswer { call_id, accept_mode, .. })) => {
-                        info!(call_id = %call_id, mode = ?accept_mode, "signal: call answered");
-                    }
-                    Ok(Some(SignalMessage::CallSetup { call_id, room, relay_addr })) => {
-                        info!(call_id = %call_id, room = %room, relay = %relay_addr, "signal: call setup");
-                        let mut s = state.lock().unwrap();
-                        s.status = "setup".into();
-                        s.call_setup_relay = Some(relay_addr);
-                        s.call_setup_room = Some(room);
-                        s.call_setup_id = Some(call_id);
-                    }
-                    Ok(Some(SignalMessage::Hangup { reason })) => {
-                        info!(reason = ?reason, "signal: hangup");
-                        let mut s = state.lock().unwrap();
-                        s.status = "registered".into();
-                        s.incoming_call_id = None;
-                        s.incoming_caller_fp = None;
-                        s.incoming_caller_alias = None;
-                        s.call_setup_relay = None;
-                        s.call_setup_room = None;
-                        s.call_setup_id = None;
-                    }
-                    Ok(Some(_)) => {}
-                    Ok(None) => {
-                        info!("signal: connection closed");
-                        break;
-                    }
-                    Err(e) => {
-                        error!("signal recv error: {e}");
-                        break;
-                    }
-                }
-            }
-
-            bg_state.lock().unwrap().status = "idle".into();
-                }); // block_on
-
-                // Runtime intentionally NOT dropped — lives until thread exits.
-                // This prevents ring/libcrypto TLS cleanup conflict on Android.
-                // The thread is parked here forever (block_on returned = connection lost).
-                std::thread::park();
-            })?; // thread spawn
-
-        // Wait for transport (up to 10s)
-        let transport = transport_rx.recv_timeout(std::time::Duration::from_secs(10))
-            .map_err(|_| anyhow::anyhow!("signal connect timeout — check relay address"))?;
-
-        Ok(Self { transport, state: ret_state, running: ret_running })
-    }
-
-    /// Get current state (non-blocking).
-    pub fn get_state(&self) -> SignalState {
-        self.state.lock().unwrap().clone()
-    }
-
-    /// Get state as JSON string.
-    pub fn get_state_json(&self) -> String {
-        serde_json::to_string(&self.get_state()).unwrap_or_else(|_| "{}".into())
-    }
-
-    /// Place a direct call.
-    pub fn place_call(&self, target_fp: &str) -> Result<(), anyhow::Error> {
-        let fp = self.state.lock().unwrap().fingerprint.clone();
-        let target = target_fp.to_string();
-        let call_id = format!("{:016x}", std::time::SystemTime::now()
-            .duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos());
-        let transport = self.transport.clone();
-
-        // Send on a small thread (async send needs a runtime)
-        std::thread::Builder::new()
-            .name("wzp-call-send".into())
-            .spawn(move || {
-                let rt = tokio::runtime::Builder::new_current_thread()
-                    .enable_all().build().expect("rt");
-                rt.block_on(async {
-                    let _ = transport.send_signal(&SignalMessage::DirectCallOffer {
-                        caller_fingerprint: fp,
-                        caller_alias: None,
-                        target_fingerprint: target,
-                        call_id,
-                        identity_pub: [0u8; 32],
-                        ephemeral_pub: [0u8; 32],
-                        signature: vec![],
-                        supported_profiles: vec![wzp_proto::QualityProfile::GOOD],
-                    }).await;
-                });
-            })?;
-        Ok(())
-    }
-
-    /// Answer an incoming call.
-    pub fn answer_call(&self, call_id: &str, mode: wzp_proto::CallAcceptMode) -> Result<(), anyhow::Error> {
-        let call_id = call_id.to_string();
-        let transport = self.transport.clone();
-
-        std::thread::Builder::new()
-            .name("wzp-answer-send".into())
-            .spawn(move || {
-                let rt = tokio::runtime::Builder::new_current_thread()
-                    .enable_all().build().expect("rt");
-                rt.block_on(async {
-                    let _ = transport.send_signal(&SignalMessage::DirectCallAnswer {
-                        call_id,
-                        accept_mode: mode,
-                        identity_pub: None,
-                        ephemeral_pub: None,
-                        signature: None,
-                        chosen_profile: Some(wzp_proto::QualityProfile::GOOD),
-                    }).await;
-                });
-            })?;
-        Ok(())
-    }
-
-    /// Send hangup.
-    pub fn hangup(&self) {
-        let transport = self.transport.clone();
-        let state = self.state.clone();
-        std::thread::spawn(move || {
-            let rt = tokio::runtime::Builder::new_current_thread()
-                .enable_all().build().expect("rt");
-            rt.block_on(async {
-                let _ = transport.send_signal(&SignalMessage::Hangup {
-                    reason: wzp_proto::HangupReason::Normal,
-                }).await;
-            });
-            let mut s = state.lock().unwrap();
-            s.status = "registered".into();
-            s.incoming_call_id = None;
-            s.incoming_caller_fp = None;
-            s.incoming_caller_alias = None;
-            s.call_setup_relay = None;
-            s.call_setup_room = None;
-            s.call_setup_id = None;
-        });
-    }
-
-    /// Stop the signal connection.
-    pub fn stop(&self) {
-        self.running.store(false, Ordering::Release);
-        self.transport.connection().close(0u32.into(), b"shutdown");
-    }
-}

crates/wzp-client/Cargo.toml

@@ -23,10 +23,71 @@ serde_json = "1"
 chrono = "0.4"
 rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
 cpal = { version = "0.15", optional = true }
+libc = "0.2"
+
+# coreaudio-rs is Apple-framework-only; gate it to macOS so enabling
+# the `vpio` feature from a non-macOS target builds cleanly instead of
+# pulling in a crate that can only link against Apple frameworks.
+[target.'cfg(target_os = "macos")'.dependencies]
+coreaudio-rs = { version = "0.11", optional = true }
+
+# Windows-only: direct WASAPI bindings for the `windows-aec` feature.
+# `windows` is Microsoft's official Rust COM bindings crate. We pull in
+# only the audio + COM subfeatures we need — the crate is organized as
+# a massive optional-feature tree, so enabling just these keeps compile
+# times reasonable (~5s for these features vs ~60s for the full crate).
+[target.'cfg(target_os = "windows")'.dependencies]
+windows = { version = "0.58", optional = true, features = [
+    "Win32_Foundation",
+    "Win32_Media_Audio",
+    "Win32_Security",
+    "Win32_System_Com",
+    "Win32_System_Com_StructuredStorage",
+    "Win32_System_Threading",
+    "Win32_System_Variant",
+] }
+
+# Linux-only: WebRTC AEC (Audio Processing Module) bindings for the
+# `linux-aec` feature. This is the 0.3.x line of the `tonarino/
+# webrtc-audio-processing` crate, which links against Debian's
+# `libwebrtc-audio-processing-dev` apt package (0.3-1+b1 on Bookworm).
+#
+# Note: we attempted the 2.x line with its `bundled` sub-feature first
+# (which would give us AEC3 instead of AEC2), but both the crates.io
+# tarball AND the upstream git `main` branch of webrtc-audio-processing-sys
+# 2.0.3 hit a `meson setup --reconfigure` bug where the build.rs passes
+# --reconfigure unconditionally even on first-run empty build dirs,
+# causing the bundled build to fail with "Directory does not contain a
+# valid build tree". The 0.x line doesn't use bundled mode and sidesteps
+# this entirely by linking the apt-provided library. AEC2 is older than
+# AEC3 but still the same algorithm family — this is what PulseAudio's
+# module-echo-cancel and PipeWire's filter-chain use by default on
+# current Debian-family distros.
+[target.'cfg(target_os = "linux")'.dependencies]
+webrtc-audio-processing = { version = "0.3", optional = true }
 
 [features]
 default = []
 audio = ["cpal"]
+# vpio enables coreaudio-rs but that dep is itself gated to macOS above,
+# so enabling this feature on Windows/Linux is a no-op (the audio_vpio
+# module is also #[cfg(target_os = "macos")] in lib.rs).
+vpio = ["dep:coreaudio-rs"]
+# windows-aec enables a direct WASAPI capture backend that opens the
+# microphone under AudioCategory_Communications, turning on Windows's
+# OS-level communications audio processing (AEC + noise suppression +
+# AGC). The `windows` dep is itself target-gated to Windows above, so
+# enabling this feature on non-Windows targets is a no-op (the
+# audio_wasapi module is also #[cfg(target_os = "windows")] in lib.rs).
+windows-aec = ["dep:windows"]
+# linux-aec enables a CPAL + WebRTC AEC3 capture/playback backend that
+# runs the WebRTC Audio Processing Module (same algo as Chrome / Zoom /
+# Teams) in-process, using the playback PCM as the reference signal for
+# echo cancellation. The webrtc-audio-processing dep is target-gated to
+# Linux above, so enabling this feature on non-Linux targets is a no-op
+# (the audio_linux_aec module is also #[cfg(target_os = "linux")] in
+# lib.rs).
+linux-aec = ["dep:webrtc-audio-processing"]
 
 [[bin]]
 name = "wzp-client"

crates/wzp-client/src/audio_io.rs

@@ -3,12 +3,10 @@
 //! Both structs use 48 kHz, mono, i16 format to match the WarzonePhone codec
 //! pipeline. Frames are 960 samples (20 ms at 48 kHz).
 //!
-//! The cpal `Stream` type is not `Send`, so each struct spawns a dedicated OS
+//! Audio callbacks are **lock-free**: they read/write directly to an `AudioRing`
-//! thread that owns the stream. The public API exposes only `Send + Sync`
+//! (atomic SPSC ring buffer). No Mutex, no channel, no allocation on the hot path.
-//! channel handles.
 
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::mpsc;
 use std::sync::Arc;
 
 use anyhow::{anyhow, Context};
@@ -16,6 +14,8 @@ use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use cpal::{SampleFormat, SampleRate, StreamConfig};
 use tracing::{info, warn};
 
+use crate::audio_ring::AudioRing;
+
 /// Number of samples per 20 ms frame at 48 kHz mono.
 pub const FRAME_SAMPLES: usize = 960;
 
@@ -23,22 +23,24 @@ pub const FRAME_SAMPLES: usize = 960;
 // AudioCapture
 // ---------------------------------------------------------------------------
 
-/// Captures microphone input and yields 960-sample PCM frames.
+/// Captures microphone input via CPAL and writes PCM into a lock-free ring buffer.
 ///
 /// The cpal stream lives on a dedicated OS thread; this handle is `Send + Sync`.
 pub struct AudioCapture {
-    rx: mpsc::Receiver<Vec<i16>>,
+    ring: Arc<AudioRing>,
     running: Arc<AtomicBool>,
 }
 
 impl AudioCapture {
     /// Create and start capturing from the default input device at 48 kHz mono.
     pub fn start() -> Result<Self, anyhow::Error> {
-        let (tx, rx) = mpsc::sync_channel::<Vec<i16>>(64);
+        let ring = Arc::new(AudioRing::new());
         let running = Arc::new(AtomicBool::new(true));
-        let running_clone = running.clone();
 
-        let (init_tx, init_rx) = mpsc::sync_channel::<Result<(), String>>(1);
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
 
         std::thread::Builder::new()
             .name("wzp-audio-capture".into())
@@ -59,53 +61,51 @@ impl AudioCapture {
 
                     let use_f32 = !supports_i16_input(&device)?;
 
-                    let buf = Arc::new(std::sync::Mutex::new(
-                        Vec::<i16>::with_capacity(FRAME_SAMPLES),
-                    ));
                     let err_cb = |e: cpal::StreamError| {
                         warn!("input stream error: {e}");
                     };
 
+                    let logged_cb_size = Arc::new(AtomicBool::new(false));
+
                     let stream = if use_f32 {
-                        let buf = buf.clone();
+                        let ring = ring_cb.clone();
-                        let tx = tx.clone();
                         let running = running_clone.clone();
+                        let logged = logged_cb_size.clone();
                         device.build_input_stream(
                             &config,
                             move |data: &[f32], _: &cpal::InputCallbackInfo| {
                                 if !running.load(Ordering::Relaxed) {
                                     return;
                                 }
-                                let mut lock = buf.lock().unwrap();
+                                if !logged.swap(true, Ordering::Relaxed) {
-                                for &s in data {
+                                    eprintln!("[audio] capture callback: {} f32 samples", data.len());
-                                    lock.push(f32_to_i16(s));
-                                    if lock.len() == FRAME_SAMPLES {
-                                        let frame = lock.drain(..).collect();
-                                        let _ = tx.try_send(frame);
                                 }
+                                let mut tmp = [0i16; FRAME_SAMPLES];
+                                for chunk in data.chunks(FRAME_SAMPLES) {
+                                    let n = chunk.len();
+                                    for i in 0..n {
+                                        tmp[i] = f32_to_i16(chunk[i]);
+                                    }
+                                    ring.write(&tmp[..n]);
                                 }
                             },
                             err_cb,
                             None,
                         )?
                     } else {
-                        let buf = buf.clone();
+                        let ring = ring_cb.clone();
-                        let tx = tx.clone();
                         let running = running_clone.clone();
+                        let logged = logged_cb_size.clone();
                         device.build_input_stream(
                             &config,
                             move |data: &[i16], _: &cpal::InputCallbackInfo| {
                                 if !running.load(Ordering::Relaxed) {
                                     return;
                                 }
-                                let mut lock = buf.lock().unwrap();
+                                if !logged.swap(true, Ordering::Relaxed) {
-                                for &s in data {
+                                    eprintln!("[audio] capture callback: {} i16 samples", data.len());
-                                    lock.push(s);
-                                    if lock.len() == FRAME_SAMPLES {
-                                        let frame = lock.drain(..).collect();
-                                        let _ = tx.try_send(frame);
-                                    }
                                 }
+                                ring.write(data);
                             },
                             err_cb,
                             None,
@@ -114,7 +114,6 @@ impl AudioCapture {
 
                     stream.play().context("failed to start input stream")?;
 
-                    // Signal success to the caller before parking.
                     let _ = init_tx.send(Ok(()));
 
                     // Keep stream alive until stopped.
@@ -135,15 +134,12 @@ impl AudioCapture {
             .map_err(|_| anyhow!("capture thread exited before signaling"))?
             .map_err(|e| anyhow!("{e}"))?;
 
-        Ok(Self { rx, running })
+        Ok(Self { ring, running })
     }
 
-    /// Read the next frame of 960 PCM samples (blocking until available).
+    /// Get a reference to the capture ring buffer for direct polling.
-    ///
+    pub fn ring(&self) -> &Arc<AudioRing> {
-    /// Returns `None` when the stream has been stopped or the channel is
+        &self.ring
-    /// disconnected.
-    pub fn read_frame(&self) -> Option<Vec<i16>> {
-        self.rx.recv().ok()
     }
 
     /// Stop capturing.
@@ -152,26 +148,34 @@ impl AudioCapture {
     }
 }
 
+impl Drop for AudioCapture {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // AudioPlayback
 // ---------------------------------------------------------------------------
 
-/// Plays PCM frames through the default output device at 48 kHz mono.
+/// Plays PCM through the default output device, reading from a lock-free ring buffer.
 ///
 /// The cpal stream lives on a dedicated OS thread; this handle is `Send + Sync`.
 pub struct AudioPlayback {
-    tx: mpsc::SyncSender<Vec<i16>>,
+    ring: Arc<AudioRing>,
     running: Arc<AtomicBool>,
 }
 
 impl AudioPlayback {
     /// Create and start playback on the default output device at 48 kHz mono.
     pub fn start() -> Result<Self, anyhow::Error> {
-        let (tx, rx) = mpsc::sync_channel::<Vec<i16>>(64);
+        let ring = Arc::new(AudioRing::new());
         let running = Arc::new(AtomicBool::new(true));
-        let running_clone = running.clone();
 
-        let (init_tx, init_rx) = mpsc::sync_channel::<Result<(), String>>(1);
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
 
         std::thread::Builder::new()
             .name("wzp-audio-playback".into())
@@ -192,62 +196,40 @@ impl AudioPlayback {
 
                     let use_f32 = !supports_i16_output(&device)?;
 
-                    // Shared ring of samples the cpal callback drains from.
-                    let ring = Arc::new(std::sync::Mutex::new(
-                        std::collections::VecDeque::<i16>::with_capacity(FRAME_SAMPLES * 8),
-                    ));
-
-                    // Background drainer: moves frames from the mpsc channel into the ring.
-                    {
-                        let ring = ring.clone();
-                        let running = running_clone.clone();
-                        std::thread::Builder::new()
-                            .name("wzp-playback-drain".into())
-                            .spawn(move || {
-                                while running.load(Ordering::Relaxed) {
-                                    match rx.recv_timeout(std::time::Duration::from_millis(100)) {
-                                        Ok(frame) => {
-                                            let mut lock = ring.lock().unwrap();
-                                            lock.extend(frame);
-                                            while lock.len() > FRAME_SAMPLES * 16 {
-                                                lock.pop_front();
-                                            }
-                                        }
-                                        Err(mpsc::RecvTimeoutError::Timeout) => {}
-                                        Err(mpsc::RecvTimeoutError::Disconnected) => break,
-                                    }
-                                }
-                            })?;
-                    }
-
                     let err_cb = |e: cpal::StreamError| {
                         warn!("output stream error: {e}");
                     };
 
                     let stream = if use_f32 {
-                        let ring = ring.clone();
+                        let ring = ring_cb.clone();
                         device.build_output_stream(
                             &config,
                             move |data: &mut [f32], _: &cpal::OutputCallbackInfo| {
-                                let mut lock = ring.lock().unwrap();
+                                let mut tmp = [0i16; FRAME_SAMPLES];
-                                for sample in data.iter_mut() {
+                                for chunk in data.chunks_mut(FRAME_SAMPLES) {
-                                    *sample = match lock.pop_front() {
+                                    let n = chunk.len();
-                                        Some(s) => i16_to_f32(s),
+                                    let read = ring.read(&mut tmp[..n]);
-                                        None => 0.0,
+                                    for i in 0..read {
-                                    };
+                                        chunk[i] = i16_to_f32(tmp[i]);
+                                    }
+                                    // Fill remainder with silence if ring underran
+                                    for i in read..n {
+                                        chunk[i] = 0.0;
+                                    }
                                 }
                             },
                             err_cb,
                             None,
                         )?
                     } else {
-                        let ring = ring.clone();
+                        let ring = ring_cb.clone();
                         device.build_output_stream(
                             &config,
                             move |data: &mut [i16], _: &cpal::OutputCallbackInfo| {
-                                let mut lock = ring.lock().unwrap();
+                                let read = ring.read(data);
-                                for sample in data.iter_mut() {
+                                // Fill remainder with silence if ring underran
-                                    *sample = lock.pop_front().unwrap_or(0);
+                                for sample in &mut data[read..] {
+                                    *sample = 0;
                                 }
                             },
                             err_cb,
@@ -257,7 +239,6 @@ impl AudioPlayback {
 
                     stream.play().context("failed to start output stream")?;
 
-                    // Signal success to the caller before parking.
                     let _ = init_tx.send(Ok(()));
 
                     // Keep stream alive until stopped.
@@ -278,12 +259,12 @@ impl AudioPlayback {
             .map_err(|_| anyhow!("playback thread exited before signaling"))?
             .map_err(|e| anyhow!("{e}"))?;
 
-        Ok(Self { tx, running })
+        Ok(Self { ring, running })
     }
 
-    /// Write a frame of PCM samples for playback.
+    /// Get a reference to the playout ring buffer for direct writing.
-    pub fn write_frame(&self, pcm: &[i16]) {
+    pub fn ring(&self) -> &Arc<AudioRing> {
-        let _ = self.tx.try_send(pcm.to_vec());
+        &self.ring
     }
 
     /// Stop playback.
@@ -292,11 +273,16 @@ impl AudioPlayback {
     }
 }
 
+impl Drop for AudioPlayback {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Helpers
 // ---------------------------------------------------------------------------
 
-/// Check if the input device supports i16 at 48 kHz mono.
 fn supports_i16_input(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     let supported = device
         .supported_input_configs()
@@ -313,7 +299,6 @@ fn supports_i16_input(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     Ok(false)
 }
 
-/// Check if the output device supports i16 at 48 kHz mono.
 fn supports_i16_output(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     let supported = device
         .supported_output_configs()

crates/wzp-client/src/audio_linux_aec.rs

@@ -0,0 +1,537 @@
+//! Linux AEC backend: CPAL capture + playback wired through the WebRTC Audio
+//! Processing Module (AEC3 + noise suppression + high-pass filter).
+//!
+//! This is the same algorithm used by Chrome WebRTC, Zoom, Teams, Jitsi, and
+//! any other "serious" Linux VoIP app. It runs in-process — no dependency on
+//! PulseAudio's module-echo-cancel or PipeWire's filter-chain, so it works
+//! identically on ALSA / PulseAudio / PipeWire systems.
+//!
+//! ## Architecture
+//!
+//! A single module-level `Arc<Mutex<Processor>>` is shared between the
+//! capture and playback paths. On each 20 ms frame (960 samples @ 48 kHz
+//! mono):
+//!
+//! - **Playback path**: `LinuxAecPlayback::start` spawns the usual CPAL
+//!   output thread, but wraps each chunk in a call to
+//!   `Processor::process_render_frame` **before** handing it to CPAL. That
+//!   gives APM an authoritative reference of exactly what's going out to
+//!   the speakers (same approach Zoom/Teams/Jitsi use). The AEC then knows
+//!   what to cancel when it sees echo in the capture stream.
+//!
+//! - **Capture path**: `LinuxAecCapture::start` spawns the usual CPAL
+//!   input thread, and runs `Processor::process_capture_frame` on each
+//!   incoming mic chunk **in place** before pushing it into the ring
+//!   buffer. The AEC subtracts the echo using the render reference it
+//!   saw on the playback side.
+//!
+//! APM is strict about frame size: it requires exactly 10 ms = 480 samples
+//! per call at 48 kHz. Our pipeline uses 20 ms = 960 samples, so each 20 ms
+//! frame is split into two 480-sample halves, APM is called twice, and the
+//! halves are stitched back together.
+//!
+//! APM only accepts f32 samples in `[-1.0, 1.0]`, so we convert i16 → f32
+//! before the call and f32 → i16 after (with clamping on the return path).
+//!
+//! ## Stream delay
+//!
+//! AEC needs to know roughly how long it takes between a sample being passed
+//! to `process_render_frame` and its echo showing up at `process_capture_frame`
+//! — i.e. the round trip through CPAL playback → speaker → air → microphone
+//! → CPAL capture. AEC3's internal estimator tracks this within a window
+//! around whatever hint we give it. We hardcode 60 ms as a reasonable
+//! starting point for typical Linux audio stacks; the delay estimator does
+//! the fine-tuning automatically.
+//!
+//! ## Thread safety
+//!
+//! The 0.3.x line of `webrtc-audio-processing` takes `&mut self` on both
+//! `process_capture_frame` and `process_render_frame`, so the `Processor`
+//! needs a `Mutex` around it for cross-thread sharing. The capture and
+//! playback threads each acquire the lock briefly (sub-millisecond per
+//! 10 ms frame) so contention is minimal at our frame rates.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex, OnceLock};
+
+use anyhow::{anyhow, Context};
+use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
+use cpal::{SampleFormat, SampleRate, StreamConfig};
+use tracing::{info, warn};
+use webrtc_audio_processing::{
+    Config, EchoCancellation, EchoCancellationSuppressionLevel, InitializationConfig,
+    NoiseSuppression, NoiseSuppressionLevel, Processor, NUM_SAMPLES_PER_FRAME,
+};
+
+use crate::audio_ring::AudioRing;
+
+/// 20 ms at 48 kHz, mono — matches the rest of the pipeline and the codec.
+pub const FRAME_SAMPLES: usize = 960;
+/// APM requires strict 10 ms frames at 48 kHz = 480 samples per call.
+/// Imported from the webrtc-audio-processing crate so we can't drift out
+/// of sync with whatever sample rate / frame length the C++ lib is using.
+const APM_FRAME_SAMPLES: usize = NUM_SAMPLES_PER_FRAME as usize;
+const APM_NUM_CHANNELS: usize = 1;
+/// Round-trip delay hint passed to APM; the estimator refines from here.
+/// 60 ms is a reasonable default for CPAL on ALSA / PulseAudio / PipeWire.
+#[allow(dead_code)]
+const STREAM_DELAY_MS: i32 = 60;
+
+// ---------------------------------------------------------------------------
+// Shared APM instance
+// ---------------------------------------------------------------------------
+
+/// Module-level lazily-initialized APM. Shared between capture and playback
+/// so they operate on the same echo-cancellation state — the render frames
+/// pushed by playback are what the capture path subtracts from the mic input.
+/// Wrapped in a Mutex because the 0.3.x Processor takes `&mut self` on both
+/// process_capture_frame and process_render_frame.
+static PROCESSOR: OnceLock<Arc<Mutex<Processor>>> = OnceLock::new();
+
+fn get_or_init_processor() -> anyhow::Result<Arc<Mutex<Processor>>> {
+    if let Some(p) = PROCESSOR.get() {
+        return Ok(p.clone());
+    }
+    let init_config = InitializationConfig {
+        num_capture_channels: APM_NUM_CHANNELS as i32,
+        num_render_channels: APM_NUM_CHANNELS as i32,
+        ..Default::default()
+    };
+    let mut processor = Processor::new(&init_config)
+        .map_err(|e| anyhow!("webrtc APM init failed: {e:?}"))?;
+
+    let config = Config {
+        echo_cancellation: Some(EchoCancellation {
+            suppression_level: EchoCancellationSuppressionLevel::High,
+            stream_delay_ms: Some(STREAM_DELAY_MS),
+            enable_delay_agnostic: true,
+            enable_extended_filter: true,
+        }),
+        noise_suppression: Some(NoiseSuppression {
+            suppression_level: NoiseSuppressionLevel::High,
+        }),
+        enable_high_pass_filter: true,
+        // AGC left off for now — it can fight the Opus encoder's own gain
+        // staging and the adaptive-quality controller. Add later if users
+        // report low mic levels.
+        ..Default::default()
+    };
+    processor.set_config(config);
+
+    let arc = Arc::new(Mutex::new(processor));
+    let _ = PROCESSOR.set(arc.clone());
+    info!(
+        stream_delay_ms = STREAM_DELAY_MS,
+        "webrtc APM initialized (AEC High + NS High + HPF, AGC off)"
+    );
+    Ok(arc)
+}
+
+// ---------------------------------------------------------------------------
+// Helpers: i16 ↔ f32 and APM frame processing
+// ---------------------------------------------------------------------------
+
+#[inline]
+fn i16_to_f32(s: i16) -> f32 {
+    s as f32 / 32768.0
+}
+
+#[inline]
+fn f32_to_i16(s: f32) -> i16 {
+    (s.clamp(-1.0, 1.0) * 32767.0) as i16
+}
+
+/// Feed a 20 ms (960-sample) playback frame to APM as the render reference.
+/// Splits into two 10 ms halves because APM is strict about frame size.
+/// Takes the Mutex-wrapped Processor and locks briefly around each call.
+fn push_render_frame_20ms(apm: &Mutex<Processor>, pcm: &[i16]) {
+    debug_assert_eq!(pcm.len(), FRAME_SAMPLES);
+    let mut buf = [0f32; APM_FRAME_SAMPLES];
+    for half in pcm.chunks_exact(APM_FRAME_SAMPLES) {
+        for (i, &s) in half.iter().enumerate() {
+            buf[i] = i16_to_f32(s);
+        }
+        match apm.lock() {
+            Ok(mut p) => {
+                if let Err(e) = p.process_render_frame(&mut buf) {
+                    warn!("webrtc APM process_render_frame failed: {e:?}");
+                }
+            }
+            Err(_) => {
+                warn!("webrtc APM mutex poisoned in render path");
+                return;
+            }
+        }
+    }
+}
+
+/// Run a 20 ms (960-sample) capture frame through APM's echo cancellation
+/// in place. Splits into two 10 ms halves, runs APM on each, stitches
+/// results back into the caller's buffer. Briefly holds the Mutex once
+/// per 10 ms half.
+fn process_capture_frame_20ms(apm: &Mutex<Processor>, pcm: &mut [i16]) {
+    debug_assert_eq!(pcm.len(), FRAME_SAMPLES);
+    let mut buf = [0f32; APM_FRAME_SAMPLES];
+    for half in pcm.chunks_exact_mut(APM_FRAME_SAMPLES) {
+        for (i, &s) in half.iter().enumerate() {
+            buf[i] = i16_to_f32(s);
+        }
+        match apm.lock() {
+            Ok(mut p) => {
+                if let Err(e) = p.process_capture_frame(&mut buf) {
+                    warn!("webrtc APM process_capture_frame failed: {e:?}");
+                }
+            }
+            Err(_) => {
+                warn!("webrtc APM mutex poisoned in capture path");
+                return;
+            }
+        }
+        for (i, d) in half.iter_mut().enumerate() {
+            *d = f32_to_i16(buf[i]);
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// LinuxAecCapture — CPAL mic + WebRTC AEC capture-side processing
+// ---------------------------------------------------------------------------
+
+/// Microphone capture with WebRTC AEC3 applied in place before the codec
+/// sees the samples. Mirrors the public API of `audio_io::AudioCapture` so
+/// downstream code doesn't change.
+pub struct LinuxAecCapture {
+    ring: Arc<AudioRing>,
+    running: Arc<AtomicBool>,
+}
+
+impl LinuxAecCapture {
+    pub fn start() -> Result<Self, anyhow::Error> {
+        // Eagerly init the APM so the playback side can find it already
+        // configured, and so init errors surface on the caller thread
+        // instead of silently failing inside the capture thread.
+        let apm = get_or_init_processor()?;
+
+        let ring = Arc::new(AudioRing::new());
+        let running = Arc::new(AtomicBool::new(true));
+
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
+        let apm_capture = apm.clone();
+
+        std::thread::Builder::new()
+            .name("wzp-audio-capture-linuxaec".into())
+            .spawn(move || {
+                let result = (|| -> Result<(), anyhow::Error> {
+                    let host = cpal::default_host();
+                    let device = host
+                        .default_input_device()
+                        .ok_or_else(|| anyhow!("no default input audio device found"))?;
+                    info!(device = %device.name().unwrap_or_default(), "LinuxAEC: using input device");
+
+                    let config = StreamConfig {
+                        channels: 1,
+                        sample_rate: SampleRate(48_000),
+                        buffer_size: cpal::BufferSize::Default,
+                    };
+
+                    let use_f32 = !supports_i16_input(&device)?;
+
+                    let err_cb = |e: cpal::StreamError| {
+                        warn!("LinuxAEC input stream error: {e}");
+                    };
+
+                    // Leftover buffer for when CPAL gives us partial frames.
+                    // We need exactly 960-sample chunks to feed APM.
+                    let leftover = std::sync::Mutex::new(Vec::<i16>::with_capacity(FRAME_SAMPLES * 4));
+
+                    let stream = if use_f32 {
+                        let ring = ring_cb.clone();
+                        let running = running_clone.clone();
+                        let apm = apm_capture.clone();
+                        device.build_input_stream(
+                            &config,
+                            move |data: &[f32], _: &cpal::InputCallbackInfo| {
+                                if !running.load(Ordering::Relaxed) {
+                                    return;
+                                }
+                                let mut lv = leftover.lock().unwrap();
+                                lv.reserve(data.len());
+                                for &s in data {
+                                    lv.push(f32_to_i16(s));
+                                }
+                                drain_frames_through_apm(&mut lv, &apm, &ring);
+                            },
+                            err_cb,
+                            None,
+                        )?
+                    } else {
+                        let ring = ring_cb.clone();
+                        let running = running_clone.clone();
+                        let apm = apm_capture.clone();
+                        device.build_input_stream(
+                            &config,
+                            move |data: &[i16], _: &cpal::InputCallbackInfo| {
+                                if !running.load(Ordering::Relaxed) {
+                                    return;
+                                }
+                                let mut lv = leftover.lock().unwrap();
+                                lv.extend_from_slice(data);
+                                drain_frames_through_apm(&mut lv, &apm, &ring);
+                            },
+                            err_cb,
+                            None,
+                        )?
+                    };
+
+                    stream.play().context("failed to start LinuxAEC input stream")?;
+                    let _ = init_tx.send(Ok(()));
+                    info!("LinuxAEC capture started (AEC3 active)");
+
+                    while running_clone.load(Ordering::Relaxed) {
+                        std::thread::park_timeout(std::time::Duration::from_millis(200));
+                    }
+                    drop(stream);
+                    Ok(())
+                })();
+
+                if let Err(e) = result {
+                    let _ = init_tx.send(Err(e.to_string()));
+                }
+            })?;
+
+        init_rx
+            .recv()
+            .map_err(|_| anyhow!("LinuxAEC capture thread exited before signaling"))?
+            .map_err(|e| anyhow!("{e}"))?;
+
+        Ok(Self { ring, running })
+    }
+
+    pub fn ring(&self) -> &Arc<AudioRing> {
+        &self.ring
+    }
+
+    pub fn stop(&self) {
+        self.running.store(false, Ordering::Relaxed);
+    }
+}
+
+impl Drop for LinuxAecCapture {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+/// Pull whole 960-sample frames out of the leftover buffer, run them through
+/// APM's capture-side processing, and push to the ring. Leaves any partial
+/// sub-960 remainder in `leftover` for the next callback.
+fn drain_frames_through_apm(leftover: &mut Vec<i16>, apm: &Mutex<Processor>, ring: &AudioRing) {
+    let mut frame = [0i16; FRAME_SAMPLES];
+    while leftover.len() >= FRAME_SAMPLES {
+        frame.copy_from_slice(&leftover[..FRAME_SAMPLES]);
+        process_capture_frame_20ms(apm, &mut frame);
+        ring.write(&frame);
+        leftover.drain(..FRAME_SAMPLES);
+    }
+}
+
+// ---------------------------------------------------------------------------
+// LinuxAecPlayback — CPAL speaker output + WebRTC AEC render-side tee
+// ---------------------------------------------------------------------------
+
+/// Speaker playback with a render-side tee: each frame written to CPAL is
+/// ALSO fed to APM via `process_render_frame` as the echo-cancellation
+/// reference signal. This is the "tee the playback ring" approach (Zoom,
+/// Teams, Jitsi) — deterministic, does not depend on PulseAudio loopback or
+/// PipeWire monitor sources.
+pub struct LinuxAecPlayback {
+    ring: Arc<AudioRing>,
+    running: Arc<AtomicBool>,
+}
+
+impl LinuxAecPlayback {
+    pub fn start() -> Result<Self, anyhow::Error> {
+        let apm = get_or_init_processor()?;
+
+        let ring = Arc::new(AudioRing::new());
+        let running = Arc::new(AtomicBool::new(true));
+
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
+        let apm_render = apm.clone();
+
+        std::thread::Builder::new()
+            .name("wzp-audio-playback-linuxaec".into())
+            .spawn(move || {
+                let result = (|| -> Result<(), anyhow::Error> {
+                    let host = cpal::default_host();
+                    let device = host
+                        .default_output_device()
+                        .ok_or_else(|| anyhow!("no default output audio device found"))?;
+                    info!(device = %device.name().unwrap_or_default(), "LinuxAEC: using output device");
+
+                    let config = StreamConfig {
+                        channels: 1,
+                        sample_rate: SampleRate(48_000),
+                        buffer_size: cpal::BufferSize::Default,
+                    };
+
+                    let use_f32 = !supports_i16_output(&device)?;
+
+                    let err_cb = |e: cpal::StreamError| {
+                        warn!("LinuxAEC output stream error: {e}");
+                    };
+
+                    // Same 960-sample batching approach as the capture side:
+                    // CPAL may ask for N samples in a callback where N doesn't
+                    // divide 960. We accumulate partial frames in a Vec and
+                    // feed APM as soon as we have a whole 20 ms frame.
+                    let carry = std::sync::Mutex::new(Vec::<i16>::with_capacity(FRAME_SAMPLES * 4));
+
+                    let stream = if use_f32 {
+                        let ring = ring_cb.clone();
+                        let apm = apm_render.clone();
+                        device.build_output_stream(
+                            &config,
+                            move |data: &mut [f32], _: &cpal::OutputCallbackInfo| {
+                                fill_output_and_tee_f32(data, &ring, &apm, &carry);
+                            },
+                            err_cb,
+                            None,
+                        )?
+                    } else {
+                        let ring = ring_cb.clone();
+                        let apm = apm_render.clone();
+                        device.build_output_stream(
+                            &config,
+                            move |data: &mut [i16], _: &cpal::OutputCallbackInfo| {
+                                fill_output_and_tee_i16(data, &ring, &apm, &carry);
+                            },
+                            err_cb,
+                            None,
+                        )?
+                    };
+
+                    stream.play().context("failed to start LinuxAEC output stream")?;
+                    let _ = init_tx.send(Ok(()));
+                    info!("LinuxAEC playback started (render tee active)");
+
+                    while running_clone.load(Ordering::Relaxed) {
+                        std::thread::park_timeout(std::time::Duration::from_millis(200));
+                    }
+                    drop(stream);
+                    Ok(())
+                })();
+
+                if let Err(e) = result {
+                    let _ = init_tx.send(Err(e.to_string()));
+                }
+            })?;
+
+        init_rx
+            .recv()
+            .map_err(|_| anyhow!("LinuxAEC playback thread exited before signaling"))?
+            .map_err(|e| anyhow!("{e}"))?;
+
+        Ok(Self { ring, running })
+    }
+
+    pub fn ring(&self) -> &Arc<AudioRing> {
+        &self.ring
+    }
+
+    pub fn stop(&self) {
+        self.running.store(false, Ordering::Relaxed);
+    }
+}
+
+impl Drop for LinuxAecPlayback {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+fn fill_output_and_tee_i16(
+    data: &mut [i16],
+    ring: &AudioRing,
+    apm: &Mutex<Processor>,
+    carry: &std::sync::Mutex<Vec<i16>>,
+) {
+    let read = ring.read(data);
+    for s in &mut data[read..] {
+        *s = 0;
+    }
+    tee_render_samples(data, apm, carry);
+}
+
+fn fill_output_and_tee_f32(
+    data: &mut [f32],
+    ring: &AudioRing,
+    apm: &Mutex<Processor>,
+    carry: &std::sync::Mutex<Vec<i16>>,
+) {
+    let mut tmp = vec![0i16; data.len()];
+    let read = ring.read(&mut tmp);
+    for s in &mut tmp[read..] {
+        *s = 0;
+    }
+    for (d, &s) in data.iter_mut().zip(tmp.iter()) {
+        *d = i16_to_f32(s);
+    }
+    tee_render_samples(&tmp, apm, carry);
+}
+
+/// Push CPAL-bound samples into APM's render-side input for echo cancellation.
+/// Uses a carry buffer to batch into exact 960-sample (20 ms) frames.
+fn tee_render_samples(samples: &[i16], apm: &Mutex<Processor>, carry: &std::sync::Mutex<Vec<i16>>) {
+    let mut lv = carry.lock().unwrap();
+    lv.extend_from_slice(samples);
+    while lv.len() >= FRAME_SAMPLES {
+        let mut frame = [0i16; FRAME_SAMPLES];
+        frame.copy_from_slice(&lv[..FRAME_SAMPLES]);
+        push_render_frame_20ms(apm, &frame);
+        lv.drain(..FRAME_SAMPLES);
+    }
+}
+
+// ---------------------------------------------------------------------------
+// CPAL format helpers (duplicated from audio_io.rs to keep the modules
+// independent — each backend file is a self-contained unit)
+// ---------------------------------------------------------------------------
+
+fn supports_i16_input(device: &cpal::Device) -> Result<bool, anyhow::Error> {
+    let supported = device
+        .supported_input_configs()
+        .context("failed to query input configs")?;
+    for cfg in supported {
+        if cfg.sample_format() == SampleFormat::I16
+            && cfg.min_sample_rate() <= SampleRate(48_000)
+            && cfg.max_sample_rate() >= SampleRate(48_000)
+            && cfg.channels() >= 1
+        {
+            return Ok(true);
+        }
+    }
+    Ok(false)
+}
+
+fn supports_i16_output(device: &cpal::Device) -> Result<bool, anyhow::Error> {
+    let supported = device
+        .supported_output_configs()
+        .context("failed to query output configs")?;
+    for cfg in supported {
+        if cfg.sample_format() == SampleFormat::I16
+            && cfg.min_sample_rate() <= SampleRate(48_000)
+            && cfg.max_sample_rate() >= SampleRate(48_000)
+            && cfg.channels() >= 1
+        {
+            return Ok(true);
+        }
+    }
+    Ok(false)
+}

crates/wzp-client/src/audio_ring.rs

@@ -0,0 +1,122 @@
+//! Lock-free SPSC ring buffer — "Reader-Detects-Lap" architecture.
+//!
+//! SPSC invariant: the producer ONLY writes `write_pos`, the consumer
+//! ONLY writes `read_pos`.  Neither thread touches the other's cursor.
+//!
+//! On overflow (writer laps the reader), the writer simply overwrites
+//! old buffer data.  The reader detects the lap via `available() >
+//! RING_CAPACITY` and snaps its own `read_pos` forward.
+//!
+//! Capacity is a power of 2 for bitmask indexing (no modulo).
+
+use std::sync::atomic::{AtomicU64, AtomicUsize, Ordering};
+
+/// Ring buffer capacity — power of 2 for bitmask indexing.
+/// 16384 samples = 341.3ms at 48kHz mono.
+const RING_CAPACITY: usize = 16384; // 2^14
+const RING_MASK: usize = RING_CAPACITY - 1;
+
+/// Lock-free single-producer single-consumer ring buffer for i16 PCM samples.
+pub struct AudioRing {
+    buf: Box<[i16]>,
+    /// Monotonically increasing write cursor. ONLY written by producer.
+    write_pos: AtomicUsize,
+    /// Monotonically increasing read cursor. ONLY written by consumer.
+    read_pos: AtomicUsize,
+    /// Incremented by reader when it detects it was lapped (overflow).
+    overflow_count: AtomicU64,
+    /// Incremented by reader when ring is empty (underrun).
+    underrun_count: AtomicU64,
+}
+
+// SAFETY: AudioRing is SPSC — one thread writes (producer), one reads (consumer).
+// The producer only writes write_pos. The consumer only writes read_pos.
+// Neither thread writes the other's cursor. Buffer indices are derived from
+// the owning thread's cursor, ensuring no concurrent access to the same index.
+unsafe impl Send for AudioRing {}
+unsafe impl Sync for AudioRing {}
+
+impl AudioRing {
+    pub fn new() -> Self {
+        debug_assert!(RING_CAPACITY.is_power_of_two());
+        Self {
+            buf: vec![0i16; RING_CAPACITY].into_boxed_slice(),
+            write_pos: AtomicUsize::new(0),
+            read_pos: AtomicUsize::new(0),
+            overflow_count: AtomicU64::new(0),
+            underrun_count: AtomicU64::new(0),
+        }
+    }
+
+    /// Number of samples available to read (clamped to capacity).
+    pub fn available(&self) -> usize {
+        let w = self.write_pos.load(Ordering::Acquire);
+        let r = self.read_pos.load(Ordering::Relaxed);
+        w.wrapping_sub(r).min(RING_CAPACITY)
+    }
+
+    /// Write samples into the ring. Returns number of samples written.
+    ///
+    /// If the ring is full, old data is silently overwritten.  The reader
+    /// will detect the lap and self-correct.  The writer NEVER touches
+    /// `read_pos`.
+    pub fn write(&self, samples: &[i16]) -> usize {
+        let count = samples.len().min(RING_CAPACITY);
+        let w = self.write_pos.load(Ordering::Relaxed);
+
+        for i in 0..count {
+            unsafe {
+                let ptr = self.buf.as_ptr() as *mut i16;
+                *ptr.add((w + i) & RING_MASK) = samples[i];
+            }
+        }
+
+        self.write_pos
+            .store(w.wrapping_add(count), Ordering::Release);
+        count
+    }
+
+    /// Read samples from the ring into `out`. Returns number of samples read.
+    ///
+    /// If the writer has lapped the reader (overflow), `read_pos` is snapped
+    /// forward to the oldest valid data.
+    pub fn read(&self, out: &mut [i16]) -> usize {
+        let w = self.write_pos.load(Ordering::Acquire);
+        let mut r = self.read_pos.load(Ordering::Relaxed);
+
+        let mut avail = w.wrapping_sub(r);
+
+        // Lap detection: writer has overwritten our unread data.
+        if avail > RING_CAPACITY {
+            r = w.wrapping_sub(RING_CAPACITY);
+            avail = RING_CAPACITY;
+            self.overflow_count.fetch_add(1, Ordering::Relaxed);
+        }
+
+        let count = out.len().min(avail);
+        if count == 0 {
+            if w == r {
+                self.underrun_count.fetch_add(1, Ordering::Relaxed);
+            }
+            return 0;
+        }
+
+        for i in 0..count {
+            out[i] = unsafe { *self.buf.as_ptr().add((r + i) & RING_MASK) };
+        }
+
+        self.read_pos
+            .store(r.wrapping_add(count), Ordering::Release);
+        count
+    }
+
+    /// Number of overflow events (reader was lapped by writer).
+    pub fn overflow_count(&self) -> u64 {
+        self.overflow_count.load(Ordering::Relaxed)
+    }
+
+    /// Number of underrun events (reader found empty buffer).
+    pub fn underrun_count(&self) -> u64 {
+        self.underrun_count.load(Ordering::Relaxed)
+    }
+}

crates/wzp-client/src/audio_vpio.rs

@@ -0,0 +1,179 @@
+//! macOS Voice Processing I/O — uses Apple's VoiceProcessingIO audio unit
+//! for hardware-accelerated echo cancellation, AGC, and noise suppression.
+//!
+//! VoiceProcessingIO is a combined input+output unit that knows what's going
+//! to the speaker, so it can cancel the echo from the mic signal internally.
+//! This is the same engine FaceTime and other Apple apps use.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+
+use anyhow::Context;
+use coreaudio::audio_unit::audio_format::LinearPcmFlags;
+use coreaudio::audio_unit::render_callback::{self, data};
+use coreaudio::audio_unit::{AudioUnit, Element, IOType, SampleFormat, Scope, StreamFormat};
+use coreaudio::sys;
+use tracing::info;
+
+use crate::audio_ring::AudioRing;
+
+/// Number of samples per 20 ms frame at 48 kHz mono.
+pub const FRAME_SAMPLES: usize = 960;
+
+/// Combined capture + playback via macOS VoiceProcessingIO.
+///
+/// The OS handles AEC internally — no manual far-end feeding needed.
+pub struct VpioAudio {
+    capture_ring: Arc<AudioRing>,
+    playout_ring: Arc<AudioRing>,
+    _audio_unit: AudioUnit,
+    running: Arc<AtomicBool>,
+}
+
+impl VpioAudio {
+    /// Start VoiceProcessingIO with AEC enabled.
+    pub fn start() -> Result<Self, anyhow::Error> {
+        let capture_ring = Arc::new(AudioRing::new());
+        let playout_ring = Arc::new(AudioRing::new());
+        let running = Arc::new(AtomicBool::new(true));
+
+        let mut au = AudioUnit::new(IOType::VoiceProcessingIO)
+            .context("failed to create VoiceProcessingIO audio unit")?;
+
+        // Must uninitialize before configuring properties.
+        au.uninitialize()
+            .context("failed to uninitialize VPIO for configuration")?;
+
+        // Enable input (mic) on Element::Input (bus 1).
+        let enable: u32 = 1;
+        au.set_property(
+            sys::kAudioOutputUnitProperty_EnableIO,
+            Scope::Input,
+            Element::Input,
+            Some(&enable),
+        )
+        .context("failed to enable VPIO input")?;
+
+        // Output (speaker) is enabled by default on VPIO, but be explicit.
+        au.set_property(
+            sys::kAudioOutputUnitProperty_EnableIO,
+            Scope::Output,
+            Element::Output,
+            Some(&enable),
+        )
+        .context("failed to enable VPIO output")?;
+
+        // Configure stream format: 48kHz mono f32 non-interleaved
+        let stream_format = StreamFormat {
+            sample_rate: 48_000.0,
+            sample_format: SampleFormat::F32,
+            flags: LinearPcmFlags::IS_FLOAT
+                | LinearPcmFlags::IS_PACKED
+                | LinearPcmFlags::IS_NON_INTERLEAVED,
+            channels: 1,
+        };
+
+        let asbd = stream_format.to_asbd();
+
+        // Input: set format on Output scope of Input element
+        // (= the format the AU delivers to us from the mic)
+        au.set_property(
+            sys::kAudioUnitProperty_StreamFormat,
+            Scope::Output,
+            Element::Input,
+            Some(&asbd),
+        )
+        .context("failed to set input stream format")?;
+
+        // Output: set format on Input scope of Output element
+        // (= the format we feed to the AU for the speaker)
+        au.set_property(
+            sys::kAudioUnitProperty_StreamFormat,
+            Scope::Input,
+            Element::Output,
+            Some(&asbd),
+        )
+        .context("failed to set output stream format")?;
+
+        // Set up input callback (mic capture with AEC applied)
+        let cap_ring = capture_ring.clone();
+        let cap_running = running.clone();
+        let logged = Arc::new(AtomicBool::new(false));
+        au.set_input_callback(
+            move |args: render_callback::Args<data::NonInterleaved<f32>>| {
+                if !cap_running.load(Ordering::Relaxed) {
+                    return Ok(());
+                }
+                let mut buffers = args.data.channels();
+                if let Some(ch) = buffers.next() {
+                    if !logged.swap(true, Ordering::Relaxed) {
+                        eprintln!("[vpio] capture callback: {} f32 samples", ch.len());
+                    }
+                    let mut tmp = [0i16; FRAME_SAMPLES];
+                    for chunk in ch.chunks(FRAME_SAMPLES) {
+                        let n = chunk.len();
+                        for i in 0..n {
+                            tmp[i] = (chunk[i].clamp(-1.0, 1.0) * i16::MAX as f32) as i16;
+                        }
+                        cap_ring.write(&tmp[..n]);
+                    }
+                }
+                Ok(())
+            },
+        )
+        .context("failed to set input callback")?;
+
+        // Set up output callback (speaker playback — AEC uses this as reference)
+        let play_ring = playout_ring.clone();
+        au.set_render_callback(
+            move |mut args: render_callback::Args<data::NonInterleaved<f32>>| {
+                let mut buffers = args.data.channels_mut();
+                if let Some(ch) = buffers.next() {
+                    let mut tmp = [0i16; FRAME_SAMPLES];
+                    for chunk in ch.chunks_mut(FRAME_SAMPLES) {
+                        let n = chunk.len();
+                        let read = play_ring.read(&mut tmp[..n]);
+                        for i in 0..read {
+                            chunk[i] = tmp[i] as f32 / i16::MAX as f32;
+                        }
+                        for i in read..n {
+                            chunk[i] = 0.0;
+                        }
+                    }
+                }
+                Ok(())
+            },
+        )
+        .context("failed to set render callback")?;
+
+        au.initialize().context("failed to initialize VoiceProcessingIO")?;
+        au.start().context("failed to start VoiceProcessingIO")?;
+
+        info!("VoiceProcessingIO started (OS-level AEC enabled)");
+
+        Ok(Self {
+            capture_ring,
+            playout_ring,
+            _audio_unit: au,
+            running,
+        })
+    }
+
+    pub fn capture_ring(&self) -> &Arc<AudioRing> {
+        &self.capture_ring
+    }
+
+    pub fn playout_ring(&self) -> &Arc<AudioRing> {
+        &self.playout_ring
+    }
+
+    pub fn stop(&self) {
+        self.running.store(false, Ordering::Relaxed);
+    }
+}
+
+impl Drop for VpioAudio {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}

crates/wzp-client/src/audio_wasapi.rs

@@ -0,0 +1,332 @@
+//! Direct WASAPI microphone capture with Windows's OS-level AEC enabled.
+//!
+//! Bypasses CPAL and opens the default capture endpoint directly via
+//! `IMMDeviceEnumerator` + `IAudioClient2::SetClientProperties`, setting
+//! `AudioClientProperties.eCategory = AudioCategory_Communications`. That's
+//! the switch that tells Windows "this is a VoIP call" — the OS then
+//! enables its communications audio processing chain (AEC, noise
+//! suppression, automatic gain control) for the stream. AEC operates at
+//! the OS level using the currently-playing audio as the reference
+//! signal, so it cancels echo from our CPAL playback (and any other app's
+//! audio) without us having to plumb a reference signal ourselves.
+//!
+//! Platform: Windows only, compiled only when the `windows-aec` feature
+//! is enabled. Mirrors the public API of `audio_io::AudioCapture` so
+//! `wzp-client`'s lib.rs can transparently re-export either one as
+//! `AudioCapture`.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+
+use anyhow::{anyhow, Context};
+use tracing::{info, warn};
+use windows::core::{Interface, GUID};
+use windows::Win32::Foundation::{CloseHandle, BOOL, WAIT_OBJECT_0};
+use windows::Win32::Media::Audio::{
+    eCapture, eCommunications, AudioCategory_Communications, AudioClientProperties,
+    IAudioCaptureClient, IAudioClient, IAudioClient2, IMMDeviceEnumerator, MMDeviceEnumerator,
+    AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM,
+    AUDCLNT_STREAMFLAGS_EVENTCALLBACK, AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY, WAVEFORMATEX,
+    WAVE_FORMAT_PCM,
+};
+use windows::Win32::System::Com::{
+    CoCreateInstance, CoInitializeEx, CoUninitialize, CLSCTX_ALL, COINIT_MULTITHREADED,
+};
+use windows::Win32::System::Threading::{CreateEventW, WaitForSingleObject, INFINITE};
+
+use crate::audio_ring::AudioRing;
+
+/// 20 ms at 48 kHz, mono. Matches the rest of the audio pipeline.
+pub const FRAME_SAMPLES: usize = 960;
+
+/// Microphone capture via WASAPI with Windows's communications AEC enabled.
+///
+/// The WASAPI capture stream runs on a dedicated OS thread. This handle is
+/// `Send + Sync`. Dropping it stops the stream and joins the thread.
+pub struct WasapiAudioCapture {
+    ring: Arc<AudioRing>,
+    running: Arc<AtomicBool>,
+    thread: Option<std::thread::JoinHandle<()>>,
+}
+
+impl WasapiAudioCapture {
+    /// Open the default communications microphone, enable OS AEC, and start
+    /// streaming PCM into a lock-free ring buffer.
+    ///
+    /// Returns only after the capture thread has successfully initialized
+    /// the stream, or propagates the error back to the caller.
+    pub fn start() -> Result<Self, anyhow::Error> {
+        let ring = Arc::new(AudioRing::new());
+        let running = Arc::new(AtomicBool::new(true));
+
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+        let ring_cb = ring.clone();
+        let running_cb = running.clone();
+
+        let thread = std::thread::Builder::new()
+            .name("wzp-audio-capture-wasapi".into())
+            .spawn(move || {
+                let result = unsafe { capture_thread_main(ring_cb, running_cb.clone(), &init_tx) };
+                if let Err(e) = result {
+                    warn!("wasapi capture thread exited with error: {e}");
+                    // If we failed before signaling init, signal now so the
+                    // caller unblocks. Double-send is harmless (channel is
+                    // bounded to 1 and we only hit the second send path on
+                    // late errors).
+                    let _ = init_tx.send(Err(e.to_string()));
+                }
+            })
+            .context("failed to spawn WASAPI capture thread")?;
+
+        init_rx
+            .recv()
+            .map_err(|_| anyhow!("WASAPI capture thread exited before signaling init"))?
+            .map_err(|e| anyhow!("{e}"))?;
+
+        Ok(Self {
+            ring,
+            running,
+            thread: Some(thread),
+        })
+    }
+
+    /// Get a reference to the capture ring buffer for direct polling.
+    pub fn ring(&self) -> &Arc<AudioRing> {
+        &self.ring
+    }
+
+    /// Stop capturing.
+    pub fn stop(&self) {
+        self.running.store(false, Ordering::Relaxed);
+    }
+}
+
+impl Drop for WasapiAudioCapture {
+    fn drop(&mut self) {
+        self.stop();
+        if let Some(handle) = self.thread.take() {
+            // Join best-effort. The thread loop polls `running` every 200ms
+            // via a short WaitForSingleObject timeout, so it should exit
+            // within ~200ms of `stop()`.
+            let _ = handle.join();
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// WASAPI thread entry point — everything below this line runs on the
+// dedicated wzp-audio-capture-wasapi thread.
+// ---------------------------------------------------------------------------
+
+unsafe fn capture_thread_main(
+    ring: Arc<AudioRing>,
+    running: Arc<AtomicBool>,
+    init_tx: &std::sync::mpsc::SyncSender<Result<(), String>>,
+) -> Result<(), anyhow::Error> {
+    // COM init for the capture thread. MULTITHREADED because we're not
+    // running a message pump. Must be balanced by CoUninitialize on exit.
+    CoInitializeEx(None, COINIT_MULTITHREADED)
+        .ok()
+        .context("CoInitializeEx failed")?;
+
+    // Use a guard struct so CoUninitialize runs even on early returns.
+    struct ComGuard;
+    impl Drop for ComGuard {
+        fn drop(&mut self) {
+            unsafe { CoUninitialize() };
+        }
+    }
+    let _com_guard = ComGuard;
+
+    let enumerator: IMMDeviceEnumerator =
+        CoCreateInstance(&MMDeviceEnumerator, None, CLSCTX_ALL)
+            .context("CoCreateInstance(MMDeviceEnumerator) failed")?;
+
+    // eCommunications role (not eConsole) — this picks the device the user
+    // has designated for communications in Sound Settings. It's the one
+    // Windows's AEC is actually tuned for and the one Teams/Zoom use.
+    let device = enumerator
+        .GetDefaultAudioEndpoint(eCapture, eCommunications)
+        .context("GetDefaultAudioEndpoint(eCapture, eCommunications) failed")?;
+
+    if let Ok(name) = device_name(&device) {
+        info!(device = %name, "opening WASAPI communications capture endpoint");
+    }
+
+    let audio_client: IAudioClient = device
+        .Activate(CLSCTX_ALL, None)
+        .context("IMMDevice::Activate(IAudioClient) failed")?;
+
+    // IAudioClient2 exposes SetClientProperties, which is the ONLY way to
+    // set AudioCategory_Communications pre-Initialize. Calling it on the
+    // base IAudioClient would not compile, and setting it after Initialize
+    // is a no-op.
+    let audio_client2: IAudioClient2 = audio_client
+        .cast()
+        .context("QueryInterface IAudioClient2 failed")?;
+
+    let mut props = AudioClientProperties {
+        cbSize: std::mem::size_of::<AudioClientProperties>() as u32,
+        bIsOffload: BOOL(0),
+        eCategory: AudioCategory_Communications,
+        // 0 = AUDCLNT_STREAMOPTIONS_NONE. The `windows` crate doesn't
+        // export the enum constant in all versions, so use 0 directly.
+        Options: Default::default(),
+    };
+    audio_client2
+        .SetClientProperties(&mut props as *mut _)
+        .context("SetClientProperties(AudioCategory_Communications) failed")?;
+
+    // Request 48 kHz mono i16 directly. AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM
+    // tells Windows to do any needed format conversion inside the audio
+    // engine rather than rejecting our format. SRC_DEFAULT_QUALITY picks
+    // the standard Windows resampler quality (fine for voice).
+    let wave_format = WAVEFORMATEX {
+        wFormatTag: WAVE_FORMAT_PCM as u16,
+        nChannels: 1,
+        nSamplesPerSec: 48_000,
+        nAvgBytesPerSec: 48_000 * 2, // 1 ch * 2 bytes/sample * 48000 Hz
+        nBlockAlign: 2,              // 1 ch * 2 bytes/sample
+        wBitsPerSample: 16,
+        cbSize: 0,
+    };
+
+    // 1,000,000 hns = 100 ms buffer (hns = 100-nanosecond units). Windows
+    // treats this as the minimum; the engine may give us a larger one.
+    const BUFFER_DURATION_HNS: i64 = 1_000_000;
+
+    audio_client
+        .Initialize(
+            AUDCLNT_SHAREMODE_SHARED,
+            AUDCLNT_STREAMFLAGS_EVENTCALLBACK
+                | AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM
+                | AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY,
+            BUFFER_DURATION_HNS,
+            0,
+            &wave_format,
+            Some(&GUID::zeroed()),
+        )
+        .context("IAudioClient::Initialize failed — Windows rejected communications-mode 48k mono i16")?;
+
+    // Event-driven capture: Windows signals this handle each time a new
+    // audio packet is available. We wait on it from the loop below.
+    let event = CreateEventW(None, false, false, None)
+        .context("CreateEventW failed")?;
+    audio_client
+        .SetEventHandle(event)
+        .context("SetEventHandle failed")?;
+
+    let capture_client: IAudioCaptureClient = audio_client
+        .GetService()
+        .context("IAudioClient::GetService(IAudioCaptureClient) failed")?;
+
+    audio_client.Start().context("IAudioClient::Start failed")?;
+
+    // Signal to the parent thread that init succeeded before entering the
+    // hot loop. From this point on, errors get logged but don't propagate
+    // back to the caller (they'd just cause the ring buffer to stop
+    // filling, which the main thread detects as underruns).
+    let _ = init_tx.send(Ok(()));
+    info!("WASAPI communications-mode capture started with OS AEC enabled");
+
+    let mut logged_first_packet = false;
+
+    // Main capture loop. Exit when `running` goes false (from Drop or an
+    // explicit stop() call).
+    while running.load(Ordering::Relaxed) {
+        // 200 ms timeout so we check `running` regularly even if the audio
+        // engine stops delivering packets (e.g. device unplugged).
+        let wait = WaitForSingleObject(event, 200);
+        if wait.0 != WAIT_OBJECT_0.0 {
+            // Timeout or failure — just loop and re-check running.
+            continue;
+        }
+
+        // Drain all available packets. Windows may have queued more than
+        // one since we were last scheduled.
+        loop {
+            let packet_length = match capture_client.GetNextPacketSize() {
+                Ok(n) => n,
+                Err(e) => {
+                    warn!("GetNextPacketSize failed: {e}");
+                    break;
+                }
+            };
+            if packet_length == 0 {
+                break;
+            }
+
+            let mut buffer_ptr: *mut u8 = std::ptr::null_mut();
+            let mut num_frames: u32 = 0;
+            let mut flags: u32 = 0;
+            let mut device_position: u64 = 0;
+            let mut qpc_position: u64 = 0;
+
+            if let Err(e) = capture_client.GetBuffer(
+                &mut buffer_ptr,
+                &mut num_frames,
+                &mut flags,
+                Some(&mut device_position),
+                Some(&mut qpc_position),
+            ) {
+                warn!("GetBuffer failed: {e}");
+                break;
+            }
+
+            if num_frames > 0 && !buffer_ptr.is_null() {
+                if !logged_first_packet {
+                    info!(
+                        frames = num_frames,
+                        flags, "WASAPI capture: first packet received"
+                    );
+                    logged_first_packet = true;
+                }
+
+                // Because we asked for 48 kHz mono i16, each frame is
+                // exactly one i16. Windows's AUTOCONVERTPCM handles the
+                // conversion from whatever the engine mix format is.
+                let samples = std::slice::from_raw_parts(
+                    buffer_ptr as *const i16,
+                    num_frames as usize,
+                );
+                ring.write(samples);
+            }
+
+            if let Err(e) = capture_client.ReleaseBuffer(num_frames) {
+                warn!("ReleaseBuffer failed: {e}");
+                break;
+            }
+        }
+    }
+
+    info!("WASAPI capture thread stopping");
+    let _ = audio_client.Stop();
+    let _ = CloseHandle(event);
+    // _com_guard drops here, calling CoUninitialize.
+
+    // Silence INFINITE unused-import warning — it's referenced by the
+    // `windows` crate's WaitForSingleObject alternative but we use the
+    // 200 ms timeout variant instead. Explicit suppression for clarity.
+    let _ = INFINITE;
+
+    Ok(())
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+/// Best-effort device ID string for logging. Grabbing the friendly name via
+/// PKEY_Device_FriendlyName requires IPropertyStore + PROPVARIANT plumbing
+/// that's far more ceremony than a log line justifies; the ID is already
+/// sufficient to confirm we opened the right endpoint.
+///
+/// Rust 2024 edition's `unsafe_op_in_unsafe_fn` lint requires explicit
+/// `unsafe { ... }` blocks inside `unsafe fn` bodies for each unsafe call,
+/// even though the whole function is already marked unsafe.
+unsafe fn device_name(
+    device: &windows::Win32::Media::Audio::IMMDevice,
+) -> Result<String, anyhow::Error> {
+    let id = unsafe { device.GetId() }.context("IMMDevice::GetId failed")?;
+    Ok(unsafe { id.to_string() }.unwrap_or_else(|_| "<non-utf16>".to_string()))
+}

crates/wzp-client/src/call.rs

@@ -43,6 +43,9 @@ pub struct CallConfig {
     /// When enabled, only every 50th frame carries a full 12-byte MediaHeader;
     /// intermediate frames use a compact 4-byte MiniHeader.
     pub mini_frames_enabled: bool,
+    /// AEC far-end delay compensation in milliseconds (default: 40).
+    /// Compensates for the round-trip audio latency from playout to mic capture.
+    pub aec_delay_ms: u32,
     /// Enable adaptive jitter buffer (default: true).
     ///
     /// When true, the jitter buffer target depth is automatically adjusted
@@ -64,6 +67,7 @@ impl Default for CallConfig {
             noise_suppression: true,
             mini_frames_enabled: true,
             adaptive_jitter: true,
+            aec_delay_ms: 40,
         }
     }
 }
@@ -242,7 +246,7 @@ impl CallEncoder {
             block_id: 0,
             frame_in_block: 0,
             timestamp_ms: 0,
-            aec: EchoCanceller::new(48000, 100), // 100 ms echo tail
+            aec: EchoCanceller::with_delay(48000, 60, config.aec_delay_ms),
             agc: AutoGainControl::new(),
             silence_detector: SilenceDetector::new(
                 config.silence_threshold_rms,
@@ -593,6 +597,52 @@ impl CallDecoder {
         }
     }
 
+    /// Switch the decoder to match an incoming packet's codec if it differs
+    /// from the current profile. This enables cross-codec interop (e.g. one
+    /// client sends Opus, the other sends Codec2).
+    fn switch_decoder_if_needed(&mut self, incoming_codec: CodecId) {
+        if incoming_codec == self.profile.codec || incoming_codec == CodecId::ComfortNoise {
+            return;
+        }
+        let new_profile = Self::profile_for_codec(incoming_codec);
+        info!(
+            from = ?self.profile.codec,
+            to = ?incoming_codec,
+            "decoder switching codec to match incoming packet"
+        );
+        if let Err(e) = self.audio_dec.set_profile(new_profile) {
+            warn!("failed to switch decoder profile: {e}");
+            return;
+        }
+        self.fec_dec = wzp_fec::create_decoder(&new_profile);
+        self.profile = new_profile;
+    }
+
+    /// Map a `CodecId` to a reasonable `QualityProfile` for decoding.
+    fn profile_for_codec(codec: CodecId) -> QualityProfile {
+        match codec {
+            CodecId::Opus24k => QualityProfile::GOOD,
+            CodecId::Opus16k => QualityProfile {
+                codec: CodecId::Opus16k,
+                fec_ratio: 0.3,
+                frame_duration_ms: 20,
+                frames_per_block: 5,
+            },
+            CodecId::Opus6k => QualityProfile::DEGRADED,
+            CodecId::Opus32k => QualityProfile::STUDIO_32K,
+            CodecId::Opus48k => QualityProfile::STUDIO_48K,
+            CodecId::Opus64k => QualityProfile::STUDIO_64K,
+            CodecId::Codec2_3200 => QualityProfile {
+                codec: CodecId::Codec2_3200,
+                fec_ratio: 0.5,
+                frame_duration_ms: 20,
+                frames_per_block: 5,
+            },
+            CodecId::Codec2_1200 => QualityProfile::CATASTROPHIC,
+            CodecId::ComfortNoise => QualityProfile::GOOD,
+        }
+    }
+
     /// Decode the next audio frame from the jitter buffer.
     ///
     /// Returns PCM samples (48kHz mono) or None if not ready.
@@ -607,6 +657,9 @@ impl CallDecoder {
                     return Some(pcm.len());
                 }
 
+                // Auto-switch decoder if incoming codec differs from current.
+                self.switch_decoder_if_needed(pkt.header.codec_id);
+
                 self.last_was_cn = false;
                 let result = match self.audio_dec.decode(&pkt.payload, pcm) {
                     Ok(n) => Some(n),

crates/wzp-client/src/cli.rs

@@ -626,11 +626,21 @@ async fn run_live(transport: Arc<wzp_transport::QuinnTransport>) -> anyhow::Resu
         .spawn(move || {
             let config = CallConfig::default();
             let mut encoder = CallEncoder::new(&config);
+            let mut frame = vec![0i16; FRAME_SAMPLES];
             loop {
-                let frame = match capture.read_frame() {
+                // Pull a full 20 ms frame from the capture ring. The ring
-                    Some(f) => f,
+                // may return a partial read when the CPAL callback hasn't
-                    None => break,
+                // produced enough samples yet — keep reading until we
-                };
+                // accumulate a whole frame, sleeping briefly on empty
+                // returns so we don't hot-spin the CPU.
+                let mut filled = 0usize;
+                while filled < FRAME_SAMPLES {
+                    let n = capture.ring().read(&mut frame[filled..]);
+                    filled += n;
+                    if n == 0 {
+                        std::thread::sleep(std::time::Duration::from_millis(2));
+                    }
+                }
                 let packets = match encoder.encode_frame(&frame) {
                     Ok(p) => p,
                     Err(e) => {
@@ -661,7 +671,13 @@ async fn run_live(transport: Arc<wzp_transport::QuinnTransport>) -> anyhow::Resu
                     // Repair packets feed the FEC decoder but don't produce audio.
                     if !is_repair {
                         if let Some(_n) = decoder.decode_next(&mut pcm_buf) {
-                            playback.write_frame(&pcm_buf);
+                            // Push the decoded frame into the playback
+                            // ring. The CPAL output callback drains from
+                            // here on its own clock; if the ring is full
+                            // (rare in CLI live mode) the write returns
+                            // a short count and the tail is dropped,
+                            // which is the correct real-time behavior.
+                            playback.ring().write(&pcm_buf);
                         }
                     }
                 }
@@ -760,7 +776,6 @@ async fn run_signal_mode(
     // Signal recv loop — handle incoming signals
     let signal_transport = transport.clone();
     let relay = relay_addr;
-    let my_fp = fp.clone();
     let my_seed = seed.0;
 
     loop {

crates/wzp-client/src/featherchat.rs

@@ -120,6 +120,12 @@ pub fn signal_to_call_type(signal: &SignalMessage) -> CallSignalType {
         SignalMessage::CallRinging { .. } => CallSignalType::Ringing,
         SignalMessage::RegisterPresence { .. }
         | SignalMessage::RegisterPresenceAck { .. } => CallSignalType::Offer, // relay-only
+        // NAT reflection is a client↔relay control exchange that
+        // never crosses the featherChat bridge — if it ever reaches
+        // this mapper something is wrong, but we still have to give
+        // an answer. "Offer" is the generic catch-all.
+        SignalMessage::Reflect
+        | SignalMessage::ReflectResponse { .. } => CallSignalType::Offer, // control-plane
     }
 }
 

crates/wzp-client/src/lib.rs

@@ -8,6 +8,24 @@
 
 #[cfg(feature = "audio")]
 pub mod audio_io;
+#[cfg(feature = "audio")]
+pub mod audio_ring;
+// VoiceProcessingIO is an Apple Core Audio API — only compile the module
+// when the `vpio` feature is on AND we're targeting macOS. Enabling the
+// feature on Windows/Linux was previously silently broken.
+#[cfg(all(feature = "vpio", target_os = "macos"))]
+pub mod audio_vpio;
+// WASAPI-direct capture with Windows's OS-level AEC (AudioCategory_Communications).
+// Only compiled when `windows-aec` feature is on AND target is Windows. The
+// `windows` dependency is itself gated to Windows in Cargo.toml, so enabling
+// this feature on non-Windows targets is a no-op.
+#[cfg(all(feature = "windows-aec", target_os = "windows"))]
+pub mod audio_wasapi;
+// WebRTC AEC3 (Audio Processing Module) wrapper around CPAL capture + playback
+// on Linux. Only compiled when `linux-aec` feature is on AND target is Linux.
+// The webrtc-audio-processing dep is itself gated to Linux in Cargo.toml.
+#[cfg(all(feature = "linux-aec", target_os = "linux"))]
+pub mod audio_linux_aec;
 pub mod bench;
 pub mod call;
 pub mod drift_test;
@@ -17,7 +35,48 @@ pub mod handshake;
 pub mod metrics;
 pub mod sweep;
 
-#[cfg(feature = "audio")]
+// AudioPlayback: three possible backends depending on feature flags.
-pub use audio_io::{AudioCapture, AudioPlayback};
+//   1. Default CPAL (`audio_io::AudioPlayback`) — baseline on every platform.
+//   2. Linux AEC (`audio_linux_aec::LinuxAecPlayback`) — CPAL + WebRTC APM
+//      render-side tee, so echo from speakers gets cancelled from the mic.
+//
+// On macOS and Windows we always use the default CPAL playback because:
+//   - macOS: VoiceProcessingIO handles AEC at the capture side (Apple's
+//     native hardware AEC uses its own reference signal handling).
+//   - Windows: WASAPI AudioCategory_Communications AEC uses the system
+//     render mix as reference — no per-process plumbing needed.
+//
+// Linux is the only platform where the in-app approach is necessary, so
+// the AEC playback path is gated to target_os = "linux".
+
+#[cfg(all(
+    feature = "audio",
+    any(not(feature = "linux-aec"), not(target_os = "linux"))
+))]
+pub use audio_io::AudioPlayback;
+
+#[cfg(all(feature = "linux-aec", target_os = "linux"))]
+pub use audio_linux_aec::LinuxAecPlayback as AudioPlayback;
+
+// AudioCapture: three possible backends depending on feature flags.
+//   1. Default CPAL (`audio_io::AudioCapture`) — baseline on every platform.
+//   2. Windows AEC (`audio_wasapi::WasapiAudioCapture`) — direct WASAPI
+//      with AudioCategory_Communications, OS APO chain does AEC.
+//   3. Linux AEC (`audio_linux_aec::LinuxAecCapture`) — CPAL + WebRTC APM
+//      capture-side echo cancellation using the playback tee as reference.
+// All three expose the same public API (`start`, `ring`, `stop`, `Drop`).
+
+#[cfg(all(
+    feature = "audio",
+    any(not(feature = "windows-aec"), not(target_os = "windows")),
+    any(not(feature = "linux-aec"), not(target_os = "linux"))
+))]
+pub use audio_io::AudioCapture;
+
+#[cfg(all(feature = "windows-aec", target_os = "windows"))]
+pub use audio_wasapi::WasapiAudioCapture as AudioCapture;
+
+#[cfg(all(feature = "linux-aec", target_os = "linux"))]
+pub use audio_linux_aec::LinuxAecCapture as AudioCapture;
 pub use call::{CallConfig, CallDecoder, CallEncoder};
 pub use handshake::perform_handshake;

crates/wzp-client/tests/handshake_integration.rs

@@ -83,12 +83,12 @@ async fn full_handshake_both_sides_derive_same_session() {
 
     // Run client and relay handshakes concurrently.
     let (client_result, relay_result) = tokio::join!(
-        wzp_client::handshake::perform_handshake(client_transport_clone.as_ref(), &client_seed),
+        wzp_client::handshake::perform_handshake(client_transport_clone.as_ref(), &client_seed, None),
         wzp_relay::handshake::accept_handshake(relay_transport_clone.as_ref(), &relay_seed),
     );
 
     let mut client_session = client_result.expect("client handshake should succeed");
-    let (mut relay_session, chosen_profile) =
+    let (mut relay_session, chosen_profile, _caller_fp, _caller_alias) =
         relay_result.expect("relay handshake should succeed");
 
     // Verify a profile was chosen.
@@ -151,6 +151,7 @@ async fn handshake_rejects_tampered_signature() {
             ephemeral_pub,
             signature: bad_signature,
             supported_profiles: vec![wzp_proto::QualityProfile::GOOD],
+            alias: None,
         };
         client_transport_clone
             .send_signal(&offer)

crates/wzp-codec/src/aec.rs

@@ -1,53 +1,127 @@
-//! Acoustic Echo Cancellation using NLMS adaptive filter.
+//! Acoustic Echo Cancellation — delay-compensated leaky NLMS with
-//! Processes 480-sample (10ms) sub-frames at 48kHz.
+//! Geigel double-talk detection.
+//!
+//! Key insight: on a laptop, the round-trip audio latency (playout → speaker
+//! → air → mic → capture) is 30–50ms.  The far-end reference must be delayed
+//! by this amount so the adaptive filter models the *echo path*, not the
+//! *system delay + echo path*.
+//!
+//! The leaky coefficient decay prevents the filter from diverging when the
+//! echo path changes (e.g. hand near laptop) or when the delay estimate
+//! is slightly off.
 
-/// NLMS (Normalized Least Mean Squares) adaptive filter echo canceller.
+/// Delay-compensated leaky NLMS echo canceller with Geigel DTD.
-///
-/// Removes acoustic echo by modelling the echo path between the far-end
-/// (speaker) signal and the near-end (microphone) signal, then subtracting
-/// the estimated echo from the near-end in real time.
 pub struct EchoCanceller {
-    filter_coeffs: Vec<f32>,
+    // --- Adaptive filter ---
+    filter: Vec<f32>,
     filter_len: usize,
-    far_end_buf: Vec<f32>,
+    /// Circular buffer of far-end reference samples (after delay).
-    far_end_pos: usize,
+    far_buf: Vec<f32>,
+    far_pos: usize,
+    /// NLMS step size.
     mu: f32,
+    /// Leakage factor: coefficients are multiplied by (1 - leak) each frame.
+    /// Prevents unbounded growth / divergence.  0.0001 is gentle.
+    leak: f32,
     enabled: bool,
+
+    // --- Delay buffer ---
+    /// Raw far-end samples before delay compensation.
+    delay_ring: Vec<f32>,
+    delay_write: usize,
+    delay_read: usize,
+    /// Delay in samples (e.g. 1920 = 40ms at 48kHz).
+    delay_samples: usize,
+    /// Capacity of the delay ring.
+    delay_cap: usize,
+
+    // --- Double-talk detection (Geigel) ---
+    /// Peak far-end level over the last filter_len samples.
+    far_peak: f32,
+    /// Geigel threshold: if |near| > threshold * far_peak, assume double-talk.
+    geigel_threshold: f32,
+    /// Holdover counter: keep DTD active for a few frames after detection.
+    dtd_holdover: u32,
+    dtd_hold_frames: u32,
 }
 
 impl EchoCanceller {
     /// Create a new echo canceller.
     ///
     /// * `sample_rate` — typically 48000
-    /// * `filter_ms`   — echo-tail length in milliseconds (e.g. 100 for 100 ms)
+    /// * `filter_ms`   — echo-tail length in milliseconds (60ms recommended)
+    /// * `delay_ms`    — far-end delay compensation in milliseconds (40ms for laptops)
     pub fn new(sample_rate: u32, filter_ms: u32) -> Self {
+        Self::with_delay(sample_rate, filter_ms, 40)
+    }
+
+    pub fn with_delay(sample_rate: u32, filter_ms: u32, delay_ms: u32) -> Self {
         let filter_len = (sample_rate as usize) * (filter_ms as usize) / 1000;
+        let delay_samples = (sample_rate as usize) * (delay_ms as usize) / 1000;
+        // Delay ring must hold at least delay_samples + one frame (960) of headroom.
+        let delay_cap = delay_samples + (sample_rate as usize / 10); // +100ms headroom
         Self {
-            filter_coeffs: vec![0.0f32; filter_len],
+            filter: vec![0.0; filter_len],
             filter_len,
-            far_end_buf: vec![0.0f32; filter_len],
+            far_buf: vec![0.0; filter_len],
-            far_end_pos: 0,
+            far_pos: 0,
             mu: 0.01,
+            leak: 0.0001,
             enabled: true,
+
+            delay_ring: vec![0.0; delay_cap],
+            delay_write: 0,
+            delay_read: 0,
+            delay_samples,
+            delay_cap,
+
+            far_peak: 0.0,
+            geigel_threshold: 0.7,
+            dtd_holdover: 0,
+            dtd_hold_frames: 5,
         }
     }
 
-    /// Feed far-end (speaker/playback) samples into the circular buffer.
+    /// Feed far-end (speaker) samples.  These go into the delay buffer first;
-    ///
+    /// once enough samples have accumulated, they are released to the filter's
-    /// Must be called with the audio that was played out through the speaker
+    /// circular buffer with the correct delay offset.
-    /// *before* the corresponding near-end frame is processed.
     pub fn feed_farend(&mut self, farend: &[i16]) {
+        // Write raw samples into the delay ring.
         for &s in farend {
-            self.far_end_buf[self.far_end_pos] = s as f32;
+            self.delay_ring[self.delay_write % self.delay_cap] = s as f32;
-            self.far_end_pos = (self.far_end_pos + 1) % self.filter_len;
+            self.delay_write += 1;
+        }
+
+        // Release delayed samples to the filter's far-end buffer.
+        while self.delay_available() >= 1 {
+            let sample = self.delay_ring[self.delay_read % self.delay_cap];
+            self.delay_read += 1;
+
+            self.far_buf[self.far_pos] = sample;
+            self.far_pos = (self.far_pos + 1) % self.filter_len;
+
+            // Track peak far-end level for Geigel DTD.
+            let abs_s = sample.abs();
+            if abs_s > self.far_peak {
+                self.far_peak = abs_s;
+            }
+        }
+
+        // Decay far_peak slowly (avoids stale peak from a loud burst long ago).
+        self.far_peak *= 0.9995;
+    }
+
+    /// Number of delayed samples available to release.
+    fn delay_available(&self) -> usize {
+        let buffered = self.delay_write - self.delay_read;
+        if buffered > self.delay_samples {
+            buffered - self.delay_samples
+        } else {
+            0
         }
     }
 
     /// Process a near-end (microphone) frame, removing the estimated echo.
-    ///
-    /// Returns the echo-return-loss enhancement (ERLE) as a ratio: the RMS of
-    /// the original near-end divided by the RMS of the residual.  Values > 1.0
-    /// mean echo was reduced.
     pub fn process_frame(&mut self, nearend: &mut [i16]) -> f32 {
         if !self.enabled {
             return 1.0;
@@ -56,85 +130,96 @@ impl EchoCanceller {
         let n = nearend.len();
         let fl = self.filter_len;
 
+        // --- Geigel double-talk detection ---
+        // If any near-end sample exceeds threshold * far_peak, assume
+        // the local speaker is active and freeze adaptation.
+        let mut is_doubletalk = self.dtd_holdover > 0;
+        if !is_doubletalk {
+            let threshold_level = self.geigel_threshold * self.far_peak;
+            for &s in nearend.iter() {
+                if (s as f32).abs() > threshold_level && self.far_peak > 100.0 {
+                    is_doubletalk = true;
+                    self.dtd_holdover = self.dtd_hold_frames;
+                    break;
+                }
+            }
+        }
+        if self.dtd_holdover > 0 {
+            self.dtd_holdover -= 1;
+        }
+
+        // Check if far-end is active (otherwise nothing to cancel).
+        let far_active = self.far_peak > 100.0;
+
+        // --- Leaky coefficient decay ---
+        // Applied once per frame for efficiency.
+        let decay = 1.0 - self.leak;
+        for c in self.filter.iter_mut() {
+            *c *= decay;
+        }
+
         let mut sum_near_sq: f64 = 0.0;
         let mut sum_err_sq: f64 = 0.0;
 
         for i in 0..n {
             let near_f = nearend[i] as f32;
 
-            // --- estimate echo as dot(coeffs, farend_window) ---
+            // Position of far-end "now" for this near-end sample.
-            // The far-end window for this sample starts at
+            let base = (self.far_pos + fl * ((n / fl) + 2) + i - n) % fl;
-            //   (far_end_pos - 1 - i) mod filter_len   (most recent)
+
-            // and goes back filter_len samples.
+            // --- Echo estimation: dot(filter, far_end_window) ---
             let mut echo_est: f32 = 0.0;
             let mut power: f32 = 0.0;
 
-            // Position of the most-recent far-end sample for this near-end sample.
-            // far_end_pos points to the *next write* position, so the most-recent
-            // sample written is at far_end_pos - 1.  We have already called
-            // feed_farend for this block, so the relevant samples are the last
-            // filter_len entries ending just before the current write position,
-            // offset by how far we are into this near-end frame.
-            //
-            // For sample i of the near-end frame, the corresponding far-end
-            // "now" is far_end_pos - n + i  (wrapping).
-            // far_end_pos points to next-write, so most recent sample is at
-            // far_end_pos - 1.  For the i-th near-end sample we want the
-            // far-end "now" to be at (far_end_pos - n + i).  We add fl
-            // repeatedly to avoid underflow on the usize subtraction.
-            let base = (self.far_end_pos + fl * ((n / fl) + 2) + i - n) % fl;
-
             for k in 0..fl {
                 let fe_idx = (base + fl - k) % fl;
-                let fe = self.far_end_buf[fe_idx];
+                let fe = self.far_buf[fe_idx];
-                echo_est += self.filter_coeffs[k] * fe;
+                echo_est += self.filter[k] * fe;
                 power += fe * fe;
             }
 
             let error = near_f - echo_est;
 
-            // --- NLMS coefficient update ---
+            // --- NLMS adaptation (only when far-end active & no double-talk) ---
-            let norm = power + 1.0; // +1 regularisation to avoid div-by-zero
+            if far_active && !is_doubletalk && power > 10.0 {
-            let step = self.mu * error / norm;
+                let step = self.mu * error / (power + 1.0);
-
                 for k in 0..fl {
                     let fe_idx = (base + fl - k) % fl;
-                let fe = self.far_end_buf[fe_idx];
+                    self.filter[k] += step * self.far_buf[fe_idx];
-                self.filter_coeffs[k] += step * fe;
+                }
             }
 
-            // Clamp output
+            let out = error.clamp(-32768.0, 32767.0);
-            let out = error.max(-32768.0).min(32767.0);
             nearend[i] = out as i16;
 
-            sum_near_sq += (near_f as f64) * (near_f as f64);
+            sum_near_sq += (near_f as f64).powi(2);
-            sum_err_sq += (out as f64) * (out as f64);
+            sum_err_sq += (out as f64).powi(2);
         }
 
-        // ERLE ratio
         if sum_err_sq < 1.0 {
-            return 100.0; // near-perfect cancellation
+            100.0
-        }
+        } else {
             (sum_near_sq / sum_err_sq).sqrt() as f32
         }
+    }
 
-    /// Enable or disable echo cancellation.
     pub fn set_enabled(&mut self, enabled: bool) {
         self.enabled = enabled;
     }
 
-    /// Returns whether echo cancellation is currently enabled.
     pub fn is_enabled(&self) -> bool {
         self.enabled
     }
 
-    /// Reset the adaptive filter to its initial state.
-    ///
-    /// Zeroes out all filter coefficients and the far-end circular buffer.
     pub fn reset(&mut self) {
-        self.filter_coeffs.iter_mut().for_each(|c| *c = 0.0);
+        self.filter.iter_mut().for_each(|c| *c = 0.0);
-        self.far_end_buf.iter_mut().for_each(|s| *s = 0.0);
+        self.far_buf.iter_mut().for_each(|s| *s = 0.0);
-        self.far_end_pos = 0;
+        self.far_pos = 0;
+        self.far_peak = 0.0;
+        self.delay_ring.iter_mut().for_each(|s| *s = 0.0);
+        self.delay_write = 0;
+        self.delay_read = 0;
+        self.dtd_holdover = 0;
     }
 }
 
@@ -143,50 +228,40 @@ mod tests {
     use super::*;
 
     #[test]
-    fn aec_creates_with_correct_filter_len() {
+    fn creates_with_correct_sizes() {
-        let aec = EchoCanceller::new(48000, 100);
+        let aec = EchoCanceller::with_delay(48000, 60, 40);
-        assert_eq!(aec.filter_len, 4800);
+        assert_eq!(aec.filter_len, 2880); // 60ms @ 48kHz
-        assert_eq!(aec.filter_coeffs.len(), 4800);
+        assert_eq!(aec.delay_samples, 1920); // 40ms @ 48kHz
-        assert_eq!(aec.far_end_buf.len(), 4800);
     }
 
     #[test]
-    fn aec_passthrough_when_disabled() {
+    fn passthrough_when_disabled() {
-        let mut aec = EchoCanceller::new(48000, 100);
+        let mut aec = EchoCanceller::new(48000, 60);
         aec.set_enabled(false);
-        assert!(!aec.is_enabled());
 
-        let original: Vec<i16> = (0..480).map(|i| (i * 10) as i16).collect();
+        let original: Vec<i16> = (0..960).map(|i| (i * 10) as i16).collect();
         let mut frame = original.clone();
-        let erle = aec.process_frame(&mut frame);
+        aec.process_frame(&mut frame);
-        assert_eq!(erle, 1.0);
         assert_eq!(frame, original);
     }
 
     #[test]
-    fn aec_reset_zeroes_state() {
+    fn silence_passthrough() {
-        let mut aec = EchoCanceller::new(48000, 10); // short for test speed
+        let mut aec = EchoCanceller::with_delay(48000, 30, 0);
-        let farend: Vec<i16> = (0..480).map(|i| ((i * 37) % 1000) as i16).collect();
+        aec.feed_farend(&vec![0i16; 960]);
-        aec.feed_farend(&farend);
+        let mut frame = vec![0i16; 960];
-
+        aec.process_frame(&mut frame);
-        aec.reset();
+        assert!(frame.iter().all(|&s| s == 0));
-
-        assert!(aec.filter_coeffs.iter().all(|&c| c == 0.0));
-        assert!(aec.far_end_buf.iter().all(|&s| s == 0.0));
-        assert_eq!(aec.far_end_pos, 0);
     }
 
     #[test]
-    fn aec_reduces_echo_of_known_signal() {
+    fn reduces_echo_with_no_delay() {
-        // Use a small filter for speed.  Feed a known far-end signal, then
+        // Simulate: far-end plays, echo arrives at mic attenuated by ~50%
-        // present the *same* signal as near-end (perfect echo, no room).
+        // (realistic — speaker to mic on laptop loses volume).
-        // After adaptation the output energy should drop.
+        let mut aec = EchoCanceller::with_delay(48000, 10, 0);
-        let filter_ms = 5; // 240 taps at 48 kHz
-        let mut aec = EchoCanceller::new(48000, filter_ms);
 
-        // Generate a simple repeating pattern.
+        let frame_len = 480;
-        let frame_len = 480usize;
+        let make_tone = |offset: usize| -> Vec<i16> {
-        let make_frame = |offset: usize| -> Vec<i16> {
             (0..frame_len)
                 .map(|i| {
                     let t = (offset + i) as f64 / 48000.0;
@@ -195,18 +270,16 @@ mod tests {
                 .collect()
         };
 
-        // Warm up the adaptive filter with several frames.
         let mut last_erle = 1.0f32;
-        for frame_idx in 0..40 {
+        for frame_idx in 0..100 {
-            let farend = make_frame(frame_idx * frame_len);
+            let farend = make_tone(frame_idx * frame_len);
             aec.feed_farend(&farend);
 
-            // Near-end = exact copy of far-end (pure echo).
+            // Near-end = attenuated copy of far-end (echo at ~50% volume).
-            let mut nearend = farend.clone();
+            let mut nearend: Vec<i16> = farend.iter().map(|&s| s / 2).collect();
             last_erle = aec.process_frame(&mut nearend);
         }
 
-        // After 40 frames the ERLE should be meaningfully > 1.
         assert!(
             last_erle > 1.0,
             "expected ERLE > 1.0 after adaptation, got {last_erle}"
@@ -214,15 +287,49 @@ mod tests {
     }
 
     #[test]
-    fn aec_silence_passthrough() {
+    fn preserves_nearend_during_doubletalk() {
-        let mut aec = EchoCanceller::new(48000, 10);
+        let mut aec = EchoCanceller::with_delay(48000, 30, 0);
-        // Feed silence far-end
+
-        aec.feed_farend(&vec![0i16; 480]);
+        let frame_len = 960;
-        // Near-end is silence too
+        let nearend: Vec<i16> = (0..frame_len)
-        let mut frame = vec![0i16; 480];
+            .map(|i| {
-        let erle = aec.process_frame(&mut frame);
+                let t = i as f64 / 48000.0;
-        assert!(erle >= 1.0);
+                (10000.0 * (2.0 * std::f64::consts::PI * 440.0 * t).sin()) as i16
-        // Output should still be silence
+            })
-        assert!(frame.iter().all(|&s| s == 0));
+            .collect();
+
+        // Feed silence as far-end (no echo source).
+        aec.feed_farend(&vec![0i16; frame_len]);
+
+        let mut frame = nearend.clone();
+        aec.process_frame(&mut frame);
+
+        let input_energy: f64 = nearend.iter().map(|&s| (s as f64).powi(2)).sum();
+        let output_energy: f64 = frame.iter().map(|&s| (s as f64).powi(2)).sum();
+        let ratio = output_energy / input_energy;
+
+        assert!(
+            ratio > 0.8,
+            "near-end speech should be preserved, energy ratio = {ratio:.3}"
+        );
+    }
+
+    #[test]
+    fn delay_buffer_holds_samples() {
+        let mut aec = EchoCanceller::with_delay(48000, 10, 20);
+        // 20ms delay = 960 samples @ 48kHz.
+        // After feeding, feed_farend auto-drains available samples to far_buf.
+        // So delay_available() is always 0 after feed_farend returns.
+        // Instead, verify far_pos advances only after the delay is filled.
+
+        // Feed 960 samples (= delay amount). No samples released yet.
+        aec.feed_farend(&vec![1i16; 960]);
+        // far_buf should still be all zeros (nothing released).
+        assert!(aec.far_buf.iter().all(|&s| s == 0.0), "nothing should be released yet");
+
+        // Feed 480 more. 480 should be released to far_buf.
+        aec.feed_farend(&vec![2i16; 480]);
+        let non_zero = aec.far_buf.iter().filter(|&&s| s != 0.0).count();
+        assert!(non_zero > 0, "samples should have been released to far_buf");
     }
 }

crates/wzp-codec/src/lib.rs

@@ -28,6 +28,26 @@ pub use denoise::NoiseSupressor;
 pub use silence::{ComfortNoise, SilenceDetector};
 pub use wzp_proto::{AudioDecoder, AudioEncoder, CodecId, QualityProfile};
 
+use std::sync::atomic::{AtomicBool, Ordering};
+
+/// Global verbose-logging flag for DRED. Off by default — when enabled
+/// (via the GUI debug toggle wired through Tauri), the encoder logs its
+/// DRED config + libopus version, and the recv path logs every DRED
+/// reconstruction, classical PLC fill, and parse heartbeat. Off in
+/// "normal" mode keeps logcat clean.
+static DRED_VERBOSE_LOGS: AtomicBool = AtomicBool::new(false);
+
+/// Returns whether DRED verbose logging is currently enabled.
+#[inline]
+pub fn dred_verbose_logs() -> bool {
+    DRED_VERBOSE_LOGS.load(Ordering::Relaxed)
+}
+
+/// Enable/disable DRED verbose logging at runtime.
+pub fn set_dred_verbose_logs(enabled: bool) {
+    DRED_VERBOSE_LOGS.store(enabled, Ordering::Relaxed);
+}
+
 /// Create an adaptive encoder starting at the given quality profile.
 ///
 /// The returned encoder accepts 48 kHz mono PCM regardless of the active

crates/wzp-codec/src/opus_enc.rs

@@ -38,10 +38,18 @@
 //! keeping the bitrate overhead modest compared to 25%. Real measurements
 //! from the quality adapter override upward when loss exceeds the floor.
 
+use std::sync::OnceLock;
+
 use opusic_c::{Application, Bitrate, Channels, Encoder, InbandFec, SampleRate, Signal};
-use tracing::{debug, warn};
+use tracing::{debug, info, warn};
 use wzp_proto::{AudioEncoder, CodecError, CodecId, QualityProfile};
 
+/// Logged exactly once per process the first time an OpusEncoder is built.
+/// Confirms that libopus 1.5.2 (the version with DRED) is actually linked
+/// at runtime — invaluable when chasing "is the new codec loaded?"
+/// regressions on Android, where the only debug surface is logcat.
+static LIBOPUS_VERSION_LOGGED: OnceLock<()> = OnceLock::new();
+
 /// Minimum `OPUS_SET_PACKET_LOSS_PERC` value used in DRED mode. libopus
 /// scales the DRED emission window with the assumed loss percentage:
 /// empirically, 5% gives a 15 ms window (useless), 10% gives 55 ms, 15%
@@ -178,7 +186,11 @@ impl OpusEncoder {
             .set_packet_loss(DRED_LOSS_FLOOR_PCT)
             .map_err(|e| CodecError::EncodeFailed(format!("set packet loss floor: {e:?}")))?;
 
-        debug!(
+        // Both of these are gated behind the GUI debug toggle so logcat
+        // stays clean in normal mode. Flip "DRED verbose logs" in the
+        // settings panel to see the per-encoder config + libopus version.
+        if crate::dred_verbose_logs() {
+            info!(
                 codec = ?codec,
                 dred_frames,
                 dred_ms = dred_frames as u32 * 10,
@@ -186,6 +198,15 @@ impl OpusEncoder {
                 "opus encoder: DRED enabled"
             );
 
+            // One-shot logging of the linked libopus version so we can
+            // confirm at a glance that opusic-c (libopus 1.5.2) is loaded.
+            // Pre-Phase-0 audiopus shipped libopus 1.3 which has no DRED;
+            // if this log says "libopus 1.3" something is very wrong.
+            LIBOPUS_VERSION_LOGGED.get_or_init(|| {
+                info!(libopus_version = %opusic_c::version(), "linked libopus version");
+            });
+        }
+
         Ok(())
     }
 

crates/wzp-crypto/tests/featherchat_compat.rs

@@ -115,6 +115,7 @@ fn wzp_signal_serializes_into_fc_callsignal_payload() {
         ephemeral_pub: [2u8; 32],
         signature: vec![3u8; 64],
         supported_profiles: vec![wzp_proto::QualityProfile::GOOD],
+        alias: None,
     };
 
     // Encode as featherChat CallSignal payload
@@ -273,13 +274,14 @@ fn auth_invalid_response_matches() {
 
 #[test]
 fn all_signal_types_map_correctly() {
-    use wzp_client::featherchat::{signal_to_call_type, CallSignalType};
+    use wzp_client::featherchat::signal_to_call_type;
 
     let cases: Vec<(wzp_proto::SignalMessage, &str)> = vec![
         (
             wzp_proto::SignalMessage::CallOffer {
                 identity_pub: [0; 32], ephemeral_pub: [0; 32],
                 signature: vec![], supported_profiles: vec![],
+                alias: None,
             },
             "Offer",
         ),

crates/wzp-native/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "wzp-native"
+version = "0.1.0"
+edition = "2024"
+description = "WarzonePhone native audio library — standalone Android cdylib that eventually owns all C++ (Oboe bridge) and exposes a pure-C FFI. Built with cargo-ndk, loaded at runtime by the Tauri desktop cdylib via libloading."
+
+# Crate-type is DELIBERATELY only cdylib (no rlib, no staticlib). This crate
+# is built with `cargo ndk -t arm64-v8a build --release -p wzp-native` as a
+# standalone .so, which is the same path the legacy wzp-android crate uses
+# successfully on the same phone / same NDK. Keeping the crate-type single
+# avoids the rust-lang/rust#104707 symbol leak that bit us when Tauri's
+# desktop crate had ["staticlib", "cdylib", "rlib"] and any C++ static
+# archive pulled bionic's internal pthread_create into the final .so.
+[lib]
+name = "wzp_native"
+crate-type = ["cdylib"]
+
+[build-dependencies]
+# cc is SAFE to use here because this crate is a single-cdylib: no
+# staticlib in crate-type → no rust-lang/rust#104707 symbol leak. The
+# legacy wzp-android crate uses the same setup and works.
+cc = "1"
+
+[dependencies]
+# Phase 2: Oboe C++ audio bridge. Still no Rust deps — we do the whole
+# audio pipeline via extern "C" into the bundled C++ and expose our own
+# narrow extern "C" API for wzp-desktop to dlopen via libloading.
+# Phase 3 can add wzp-proto/wzp-codec if we want to share codec logic
+# instead of calling back into wzp-desktop via callbacks.

crates/wzp-native/build.rs

@@ -0,0 +1,119 @@
+//! wzp-native build.rs — Oboe C++ bridge compile on Android.
+//!
+//! Near-verbatim copy of crates/wzp-android/build.rs (which is known to
+//! work). The crucial distinction: this crate is a single-cdylib (no
+//! staticlib, no rlib in crate-type) so rust-lang/rust#104707 doesn't
+//! apply — bionic's internal pthread_create / __init_tcb symbols stay
+//! UND and resolve against libc.so at runtime, as they should.
+//!
+//! On non-Android hosts we compile `cpp/oboe_stub.cpp` (empty stubs) so
+//! `cargo check --target <host>` still works for IDEs and CI.
+
+use std::path::PathBuf;
+
+fn main() {
+    let target = std::env::var("TARGET").unwrap_or_default();
+
+    if target.contains("android") {
+        // getauxval_fix: override compiler-rt's broken static getauxval
+        // stub that SIGSEGVs in shared libraries.
+        cc::Build::new()
+            .file("cpp/getauxval_fix.c")
+            .compile("wzp_native_getauxval_fix");
+
+        let oboe_dir = fetch_oboe();
+        match oboe_dir {
+            Some(oboe_path) => {
+                println!("cargo:warning=wzp-native: building with Oboe from {:?}", oboe_path);
+                let mut build = cc::Build::new();
+                build
+                    .cpp(true)
+                    .std("c++17")
+                    // Shared libc++ — matches legacy wzp-android setup.
+                    .cpp_link_stdlib(Some("c++_shared"))
+                    .include("cpp")
+                    .include(oboe_path.join("include"))
+                    .include(oboe_path.join("src"))
+                    .define("WZP_HAS_OBOE", None)
+                    .file("cpp/oboe_bridge.cpp");
+                add_cpp_files_recursive(&mut build, &oboe_path.join("src"));
+                build.compile("wzp_native_oboe_bridge");
+            }
+            None => {
+                println!("cargo:warning=wzp-native: Oboe not found, building stub");
+                cc::Build::new()
+                    .cpp(true)
+                    .std("c++17")
+                    .cpp_link_stdlib(Some("c++_shared"))
+                    .file("cpp/oboe_stub.cpp")
+                    .include("cpp")
+                    .compile("wzp_native_oboe_bridge");
+            }
+        }
+
+        // Oboe needs log + OpenSLES backends at runtime.
+        println!("cargo:rustc-link-lib=log");
+        println!("cargo:rustc-link-lib=OpenSLES");
+
+        // Re-run if any cpp file changes
+        println!("cargo:rerun-if-changed=cpp/oboe_bridge.cpp");
+        println!("cargo:rerun-if-changed=cpp/oboe_bridge.h");
+        println!("cargo:rerun-if-changed=cpp/oboe_stub.cpp");
+        println!("cargo:rerun-if-changed=cpp/getauxval_fix.c");
+    } else {
+        // Non-Android hosts: compile the empty stub so lib.rs's extern
+        // declarations resolve when someone runs `cargo check` on macOS
+        // or Linux without an NDK.
+        cc::Build::new()
+            .cpp(true)
+            .std("c++17")
+            .file("cpp/oboe_stub.cpp")
+            .include("cpp")
+            .compile("wzp_native_oboe_bridge");
+        println!("cargo:rerun-if-changed=cpp/oboe_stub.cpp");
+    }
+}
+
+/// Recursively add all `.cpp` files from a directory to a cc::Build.
+fn add_cpp_files_recursive(build: &mut cc::Build, dir: &std::path::Path) {
+    if !dir.is_dir() {
+        return;
+    }
+    for entry in std::fs::read_dir(dir).unwrap() {
+        let entry = entry.unwrap();
+        let path = entry.path();
+        if path.is_dir() {
+            add_cpp_files_recursive(build, &path);
+        } else if path.extension().map_or(false, |e| e == "cpp") {
+            build.file(&path);
+        }
+    }
+}
+
+/// Fetch or find Oboe headers + sources (v1.8.1). Same logic as the
+/// legacy wzp-android crate's build.rs.
+fn fetch_oboe() -> Option<PathBuf> {
+    let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
+    let oboe_dir = out_dir.join("oboe");
+
+    if oboe_dir.join("include").join("oboe").join("Oboe.h").exists() {
+        return Some(oboe_dir);
+    }
+
+    let status = std::process::Command::new("git")
+        .args([
+            "clone",
+            "--depth=1",
+            "--branch=1.8.1",
+            "https://github.com/google/oboe.git",
+            oboe_dir.to_str().unwrap(),
+        ])
+        .status();
+
+    match status {
+        Ok(s) if s.success() && oboe_dir.join("include").join("oboe").join("Oboe.h").exists() => {
+            Some(oboe_dir)
+        }
+        _ => None,
+    }
+}

crates/wzp-native/cpp/getauxval_fix.c

@@ -0,0 +1,21 @@
+// Override the broken static getauxval from compiler-rt/CRT.
+// The static version reads from __libc_auxv which is NULL in shared libs
+// loaded via dlopen, causing SIGSEGV in init_have_lse_atomics at load time.
+// This version calls the real bionic getauxval via dlsym.
+#ifdef __ANDROID__
+#include <dlfcn.h>
+#include <stdint.h>
+
+typedef unsigned long (*getauxval_fn)(unsigned long);
+
+unsigned long getauxval(unsigned long type) {
+    static getauxval_fn real_getauxval = (getauxval_fn)0;
+    if (!real_getauxval) {
+        real_getauxval = (getauxval_fn)dlsym((void*)-1L /* RTLD_DEFAULT */, "getauxval");
+        if (!real_getauxval) {
+            return 0;
+        }
+    }
+    return real_getauxval(type);
+}
+#endif

crates/wzp-native/cpp/oboe_bridge.cpp

@@ -0,0 +1,420 @@
+// Full Oboe implementation for Android
+// This file is compiled only when targeting Android
+
+#include "oboe_bridge.h"
+
+#ifdef __ANDROID__
+#include <oboe/Oboe.h>
+#include <android/log.h>
+#include <cstring>
+#include <atomic>
+
+#define LOG_TAG "wzp-oboe"
+#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
+#define LOGW(...) __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)
+#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
+
+// ---------------------------------------------------------------------------
+// Ring buffer helpers (SPSC, lock-free)
+// ---------------------------------------------------------------------------
+
+static inline int32_t ring_available_read(const wzp_atomic_int* write_idx,
+                                           const wzp_atomic_int* read_idx,
+                                           int32_t capacity) {
+    int32_t w = std::atomic_load_explicit(write_idx, std::memory_order_acquire);
+    int32_t r = std::atomic_load_explicit(read_idx, std::memory_order_relaxed);
+    int32_t avail = w - r;
+    if (avail < 0) avail += capacity;
+    return avail;
+}
+
+static inline int32_t ring_available_write(const wzp_atomic_int* write_idx,
+                                            const wzp_atomic_int* read_idx,
+                                            int32_t capacity) {
+    return capacity - 1 - ring_available_read(write_idx, read_idx, capacity);
+}
+
+static inline void ring_write(int16_t* buf, int32_t capacity,
+                               wzp_atomic_int* write_idx, const wzp_atomic_int* read_idx,
+                               const int16_t* src, int32_t count) {
+    int32_t w = std::atomic_load_explicit(write_idx, std::memory_order_relaxed);
+    for (int32_t i = 0; i < count; i++) {
+        buf[w] = src[i];
+        w++;
+        if (w >= capacity) w = 0;
+    }
+    std::atomic_store_explicit(write_idx, w, std::memory_order_release);
+}
+
+static inline void ring_read(int16_t* buf, int32_t capacity,
+                              const wzp_atomic_int* write_idx, wzp_atomic_int* read_idx,
+                              int16_t* dst, int32_t count) {
+    int32_t r = std::atomic_load_explicit(read_idx, std::memory_order_relaxed);
+    for (int32_t i = 0; i < count; i++) {
+        dst[i] = buf[r];
+        r++;
+        if (r >= capacity) r = 0;
+    }
+    std::atomic_store_explicit(read_idx, r, std::memory_order_release);
+}
+
+// ---------------------------------------------------------------------------
+// Global state
+// ---------------------------------------------------------------------------
+
+static std::shared_ptr<oboe::AudioStream> g_capture_stream;
+static std::shared_ptr<oboe::AudioStream> g_playout_stream;
+// Value copy — the WzpOboeRings the Rust side passes us lives on the caller's
+// stack frame and goes away as soon as wzp_oboe_start returns. The raw
+// int16/atomic pointers INSIDE the struct point into the Rust-owned, leaked-
+// for-the-lifetime-of-the-process AudioBackend singleton, so copying the
+// struct by value is safe and keeps the inner pointers valid indefinitely.
+// g_rings_valid guards the audio-callback-side read; clearing it in stop()
+// signals "no backend" to the callbacks which then return silence + Stop.
+static WzpOboeRings g_rings{};
+static std::atomic<bool> g_rings_valid{false};
+static std::atomic<bool> g_running{false};
+static std::atomic<float> g_capture_latency_ms{0.0f};
+static std::atomic<float> g_playout_latency_ms{0.0f};
+
+// ---------------------------------------------------------------------------
+// Capture callback
+// ---------------------------------------------------------------------------
+
+class CaptureCallback : public oboe::AudioStreamDataCallback {
+public:
+    uint64_t calls = 0;
+    uint64_t total_frames = 0;
+    uint64_t total_written = 0;
+    uint64_t ring_full_drops = 0;
+
+    oboe::DataCallbackResult onAudioReady(
+            oboe::AudioStream* stream,
+            void* audioData,
+            int32_t numFrames) override {
+        if (!g_running.load(std::memory_order_relaxed) ||
+            !g_rings_valid.load(std::memory_order_acquire)) {
+            return oboe::DataCallbackResult::Stop;
+        }
+
+        const int16_t* src = static_cast<const int16_t*>(audioData);
+        int32_t avail = ring_available_write(g_rings.capture_write_idx,
+                                              g_rings.capture_read_idx,
+                                              g_rings.capture_capacity);
+        int32_t to_write = (numFrames < avail) ? numFrames : avail;
+        if (to_write > 0) {
+            ring_write(g_rings.capture_buf, g_rings.capture_capacity,
+                       g_rings.capture_write_idx, g_rings.capture_read_idx,
+                       src, to_write);
+        }
+        total_frames += numFrames;
+        total_written += to_write;
+        if (to_write < numFrames) {
+            ring_full_drops += (numFrames - to_write);
+        }
+
+        // Sample-range probe on the FIRST callback to prove we get real audio
+        if (calls == 0 && numFrames > 0) {
+            int16_t lo = src[0], hi = src[0];
+            int32_t sumsq = 0;
+            for (int32_t i = 0; i < numFrames; i++) {
+                if (src[i] < lo) lo = src[i];
+                if (src[i] > hi) hi = src[i];
+                sumsq += (int32_t)src[i] * (int32_t)src[i];
+            }
+            int32_t rms = (int32_t) (numFrames > 0 ? (int32_t)__builtin_sqrt((double)sumsq / (double)numFrames) : 0);
+            LOGI("capture cb#0: numFrames=%d sample_range=[%d..%d] rms=%d to_write=%d",
+                 numFrames, lo, hi, rms, to_write);
+        }
+        // Heartbeat every 50 callbacks (~1s at 20ms/burst)
+        calls++;
+        if ((calls % 50) == 0) {
+            LOGI("capture heartbeat: calls=%llu numFrames=%d ring_avail_write=%d to_write=%d full_drops=%llu total_written=%llu",
+                 (unsigned long long)calls, numFrames, avail, to_write,
+                 (unsigned long long)ring_full_drops, (unsigned long long)total_written);
+        }
+
+        // Update latency estimate
+        auto result = stream->calculateLatencyMillis();
+        if (result) {
+            g_capture_latency_ms.store(static_cast<float>(result.value()),
+                                        std::memory_order_relaxed);
+        }
+
+        return oboe::DataCallbackResult::Continue;
+    }
+};
+
+// ---------------------------------------------------------------------------
+// Playout callback
+// ---------------------------------------------------------------------------
+
+class PlayoutCallback : public oboe::AudioStreamDataCallback {
+public:
+    uint64_t calls = 0;
+    uint64_t total_frames = 0;
+    uint64_t total_played_real = 0;
+    uint64_t underrun_frames = 0;
+    uint64_t nonempty_calls = 0;
+
+    oboe::DataCallbackResult onAudioReady(
+            oboe::AudioStream* stream,
+            void* audioData,
+            int32_t numFrames) override {
+        if (!g_running.load(std::memory_order_relaxed) ||
+            !g_rings_valid.load(std::memory_order_acquire)) {
+            memset(audioData, 0, numFrames * sizeof(int16_t));
+            return oboe::DataCallbackResult::Stop;
+        }
+
+        int16_t* dst = static_cast<int16_t*>(audioData);
+        int32_t avail = ring_available_read(g_rings.playout_write_idx,
+                                             g_rings.playout_read_idx,
+                                             g_rings.playout_capacity);
+        int32_t to_read = (numFrames < avail) ? numFrames : avail;
+
+        if (to_read > 0) {
+            ring_read(g_rings.playout_buf, g_rings.playout_capacity,
+                      g_rings.playout_write_idx, g_rings.playout_read_idx,
+                      dst, to_read);
+            nonempty_calls++;
+        }
+        // Fill remainder with silence on underrun
+        if (to_read < numFrames) {
+            memset(dst + to_read, 0, (numFrames - to_read) * sizeof(int16_t));
+            underrun_frames += (numFrames - to_read);
+        }
+        total_frames += numFrames;
+        total_played_real += to_read;
+
+        // First callback: log requested config + prove we're being called
+        if (calls == 0) {
+            LOGI("playout cb#0: numFrames=%d ring_avail_read=%d to_read=%d",
+                 numFrames, avail, to_read);
+        }
+        // On the first callback that actually has data, log the sample range
+        // so we can tell if the samples coming out of the ring look like real
+        // audio vs constant-zeroes vs garbage.
+        if (to_read > 0 && nonempty_calls == 1) {
+            int16_t lo = dst[0], hi = dst[0];
+            int32_t sumsq = 0;
+            for (int32_t i = 0; i < to_read; i++) {
+                if (dst[i] < lo) lo = dst[i];
+                if (dst[i] > hi) hi = dst[i];
+                sumsq += (int32_t)dst[i] * (int32_t)dst[i];
+            }
+            int32_t rms = (to_read > 0) ? (int32_t)__builtin_sqrt((double)sumsq / (double)to_read) : 0;
+            LOGI("playout FIRST nonempty read: to_read=%d sample_range=[%d..%d] rms=%d",
+                 to_read, lo, hi, rms);
+        }
+        // Heartbeat every 50 callbacks (~1s at 20ms/burst)
+        calls++;
+        if ((calls % 50) == 0) {
+            int state = (int)stream->getState();
+            auto xrunRes = stream->getXRunCount();
+            int xruns = xrunRes ? xrunRes.value() : -1;
+            LOGI("playout heartbeat: calls=%llu nonempty=%llu numFrames=%d ring_avail_read=%d to_read=%d underrun_frames=%llu total_played_real=%llu state=%d xruns=%d",
+                 (unsigned long long)calls, (unsigned long long)nonempty_calls,
+                 numFrames, avail, to_read,
+                 (unsigned long long)underrun_frames, (unsigned long long)total_played_real,
+                 state, xruns);
+        }
+
+        // Update latency estimate
+        auto result = stream->calculateLatencyMillis();
+        if (result) {
+            g_playout_latency_ms.store(static_cast<float>(result.value()),
+                                        std::memory_order_relaxed);
+        }
+
+        return oboe::DataCallbackResult::Continue;
+    }
+};
+
+static CaptureCallback g_capture_cb;
+static PlayoutCallback g_playout_cb;
+
+// ---------------------------------------------------------------------------
+// Public C API
+// ---------------------------------------------------------------------------
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings) {
+    if (g_running.load(std::memory_order_relaxed)) {
+        LOGW("wzp_oboe_start: already running");
+        return -1;
+    }
+
+    // Deep-copy the rings struct into static storage BEFORE we publish it to
+    // the audio callbacks — `rings` points at the caller's stack frame and
+    // goes away as soon as this function returns.
+    g_rings = *rings;
+    g_rings_valid.store(true, std::memory_order_release);
+
+    // Build capture stream
+    oboe::AudioStreamBuilder captureBuilder;
+    captureBuilder.setDirection(oboe::Direction::Input)
+        ->setPerformanceMode(oboe::PerformanceMode::LowLatency)
+        ->setSharingMode(oboe::SharingMode::Exclusive)
+        ->setFormat(oboe::AudioFormat::I16)
+        ->setChannelCount(config->channel_count)
+        ->setSampleRate(config->sample_rate)
+        ->setFramesPerDataCallback(config->frames_per_burst)
+        ->setInputPreset(oboe::InputPreset::VoiceCommunication)
+        ->setDataCallback(&g_capture_cb);
+
+    oboe::Result result = captureBuilder.openStream(g_capture_stream);
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to open capture stream: %s", oboe::convertToText(result));
+        return -2;
+    }
+    LOGI("capture stream opened: actualSR=%d actualCh=%d actualFormat=%d actualFramesPerBurst=%d actualFramesPerDataCallback=%d bufferCapacityInFrames=%d sharing=%d perfMode=%d",
+         g_capture_stream->getSampleRate(),
+         g_capture_stream->getChannelCount(),
+         (int)g_capture_stream->getFormat(),
+         g_capture_stream->getFramesPerBurst(),
+         g_capture_stream->getFramesPerDataCallback(),
+         g_capture_stream->getBufferCapacityInFrames(),
+         (int)g_capture_stream->getSharingMode(),
+         (int)g_capture_stream->getPerformanceMode());
+
+    // Build playout stream.
+    //
+    // Regression triangulation between builds:
+    //   96be740 (Usage::Media, default API): playout callback DID drain
+    //   the ring at steady 50Hz (playout heartbeat: calls=1100,
+    //   total_played_real=1055040). Audio not audible because OS routing
+    //   sent it to a silent output.
+    //
+    //   8c36fb5 (Usage::VoiceCommunication + setAudioApi(AAudio) +
+    //   ContentType::Speech): playout callback fired cb#0 once then
+    //   stopped draining the ring entirely. written_samples stuck at
+    //   ring capacity (7679) across all subsequent heartbeats, so Oboe
+    //   accepted zero samples after startup. Still inaudible.
+    //
+    // Hypothesis: forcing setAudioApi(AAudio) + VoiceCommunication on
+    // Pixel 6 / Android 15 opens a stream that succeeds at cb#0 but
+    // then detaches from the real audio driver. Reverting to the
+    // config that at least drove callbacks correctly, plus the
+    // Kotlin-side MODE_IN_COMMUNICATION + setSpeakerphoneOn(true)
+    // handled in MainActivity.kt to route audio to the loud speaker.
+    // Usage::VoiceCommunication is the correct Oboe usage for a VoIP app
+    // — it respects Android's in-call audio routing and lets
+    // AudioManager.setSpeakerphoneOn/setBluetoothScoOn actually switch
+    // between earpiece, loudspeaker, and Bluetooth headset. Combined with
+    // MODE_IN_COMMUNICATION set from MainActivity.kt and
+    // speakerphoneOn=false by default, this produces handset/earpiece as
+    // the default output.
+    //
+    // IMPORTANT: do NOT add setAudioApi(AAudio) here. Build 8c36fb5 proved
+    // forcing AAudio with Usage::VoiceCommunication makes the playout
+    // callback stop draining the ring after cb#0, even though the stream
+    // opens successfully. Letting Oboe pick the API (which will be AAudio
+    // on API ≥ 27 but via a different codepath) kept callbacks firing in
+    // every other build.
+    oboe::AudioStreamBuilder playoutBuilder;
+    playoutBuilder.setDirection(oboe::Direction::Output)
+        ->setPerformanceMode(oboe::PerformanceMode::LowLatency)
+        ->setSharingMode(oboe::SharingMode::Exclusive)
+        ->setFormat(oboe::AudioFormat::I16)
+        ->setChannelCount(config->channel_count)
+        ->setSampleRate(config->sample_rate)
+        ->setFramesPerDataCallback(config->frames_per_burst)
+        ->setUsage(oboe::Usage::VoiceCommunication)
+        ->setDataCallback(&g_playout_cb);
+
+    result = playoutBuilder.openStream(g_playout_stream);
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to open playout stream: %s", oboe::convertToText(result));
+        g_capture_stream->close();
+        g_capture_stream.reset();
+        return -3;
+    }
+    LOGI("playout stream opened: actualSR=%d actualCh=%d actualFormat=%d actualFramesPerBurst=%d actualFramesPerDataCallback=%d bufferCapacityInFrames=%d sharing=%d perfMode=%d",
+         g_playout_stream->getSampleRate(),
+         g_playout_stream->getChannelCount(),
+         (int)g_playout_stream->getFormat(),
+         g_playout_stream->getFramesPerBurst(),
+         g_playout_stream->getFramesPerDataCallback(),
+         g_playout_stream->getBufferCapacityInFrames(),
+         (int)g_playout_stream->getSharingMode(),
+         (int)g_playout_stream->getPerformanceMode());
+
+    g_running.store(true, std::memory_order_release);
+
+    // Start both streams
+    result = g_capture_stream->requestStart();
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to start capture: %s", oboe::convertToText(result));
+        g_running.store(false, std::memory_order_release);
+        g_capture_stream->close();
+        g_playout_stream->close();
+        g_capture_stream.reset();
+        g_playout_stream.reset();
+        return -4;
+    }
+
+    result = g_playout_stream->requestStart();
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to start playout: %s", oboe::convertToText(result));
+        g_running.store(false, std::memory_order_release);
+        g_capture_stream->requestStop();
+        g_capture_stream->close();
+        g_playout_stream->close();
+        g_capture_stream.reset();
+        g_playout_stream.reset();
+        return -5;
+    }
+
+    LOGI("Oboe started: sr=%d burst=%d ch=%d",
+         config->sample_rate, config->frames_per_burst, config->channel_count);
+    return 0;
+}
+
+void wzp_oboe_stop(void) {
+    g_running.store(false, std::memory_order_release);
+    // Tell the audio callbacks to stop touching g_rings BEFORE we tear down
+    // the streams, so any in-flight callback returns Stop instead of reading
+    // stale pointers.
+    g_rings_valid.store(false, std::memory_order_release);
+
+    if (g_capture_stream) {
+        g_capture_stream->requestStop();
+        g_capture_stream->close();
+        g_capture_stream.reset();
+    }
+    if (g_playout_stream) {
+        g_playout_stream->requestStop();
+        g_playout_stream->close();
+        g_playout_stream.reset();
+    }
+
+    LOGI("Oboe stopped");
+}
+
+float wzp_oboe_capture_latency_ms(void) {
+    return g_capture_latency_ms.load(std::memory_order_relaxed);
+}
+
+float wzp_oboe_playout_latency_ms(void) {
+    return g_playout_latency_ms.load(std::memory_order_relaxed);
+}
+
+int wzp_oboe_is_running(void) {
+    return g_running.load(std::memory_order_relaxed) ? 1 : 0;
+}
+
+#else
+// Non-Android fallback — should not be reached; oboe_stub.cpp is used instead.
+// Provide empty implementations just in case.
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings) {
+    (void)config; (void)rings;
+    return -99;
+}
+
+void wzp_oboe_stop(void) {}
+float wzp_oboe_capture_latency_ms(void) { return 0.0f; }
+float wzp_oboe_playout_latency_ms(void) { return 0.0f; }
+int wzp_oboe_is_running(void) { return 0; }
+
+#endif // __ANDROID__

crates/wzp-native/cpp/oboe_bridge.h

@@ -0,0 +1,43 @@
+#ifndef WZP_OBOE_BRIDGE_H
+#define WZP_OBOE_BRIDGE_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+#include <atomic>
+typedef std::atomic<int32_t> wzp_atomic_int;
+extern "C" {
+#else
+#include <stdatomic.h>
+typedef atomic_int wzp_atomic_int;
+#endif
+
+typedef struct {
+    int32_t sample_rate;
+    int32_t frames_per_burst;
+    int32_t channel_count;
+} WzpOboeConfig;
+
+typedef struct {
+    int16_t* capture_buf;
+    int32_t  capture_capacity;
+    wzp_atomic_int* capture_write_idx;
+    wzp_atomic_int* capture_read_idx;
+
+    int16_t* playout_buf;
+    int32_t  playout_capacity;
+    wzp_atomic_int* playout_write_idx;
+    wzp_atomic_int* playout_read_idx;
+} WzpOboeRings;
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings);
+void wzp_oboe_stop(void);
+float wzp_oboe_capture_latency_ms(void);
+float wzp_oboe_playout_latency_ms(void);
+int wzp_oboe_is_running(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // WZP_OBOE_BRIDGE_H

crates/wzp-native/cpp/oboe_stub.cpp

@@ -0,0 +1,27 @@
+// Stub implementation for non-Android host builds (testing, cargo check, etc.)
+
+#include "oboe_bridge.h"
+#include <stdio.h>
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings) {
+    (void)config;
+    (void)rings;
+    fprintf(stderr, "wzp_oboe_start: stub (not on Android)\n");
+    return 0;
+}
+
+void wzp_oboe_stop(void) {
+    fprintf(stderr, "wzp_oboe_stop: stub (not on Android)\n");
+}
+
+float wzp_oboe_capture_latency_ms(void) {
+    return 0.0f;
+}
+
+float wzp_oboe_playout_latency_ms(void) {
+    return 0.0f;
+}
+
+int wzp_oboe_is_running(void) {
+    return 0;
+}

crates/wzp-native/src/lib.rs

@@ -0,0 +1,331 @@
+//! wzp-native — standalone Android cdylib for all the C++ audio code.
+//!
+//! Built with `cargo ndk`, NOT `cargo tauri android build`. Loaded at
+//! runtime by the Tauri desktop cdylib (`wzp-desktop`) via libloading.
+//! See `docs/incident-tauri-android-init-tcb.md` for why the split exists.
+//!
+//! Phase 2: real Oboe audio backend.
+//!
+//! Architecture: Oboe runs capture + playout streams on its own high-
+//! priority AAudio callback threads inside the C++ bridge. Two SPSC ring
+//! buffers (capture and playout) are shared between the C++ callbacks
+//! and the Rust side via atomic indices — no locks on the hot path.
+//! `wzp-desktop` drains the capture ring into its Opus encoder and fills
+//! the playout ring with decoded PCM.
+
+use std::sync::atomic::{AtomicI32, Ordering};
+
+// ─── Phase 1 smoke-test exports (kept for sanity checks) ─────────────────
+
+/// Returns 42. Used by wzp-desktop's setup() to verify dlopen + dlsym
+/// work before any audio code runs.
+#[unsafe(no_mangle)]
+pub extern "C" fn wzp_native_version() -> i32 {
+    42
+}
+
+/// Writes a NUL-terminated string into `out` (capped at `cap`) and
+/// returns bytes written excluding the NUL.
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn wzp_native_hello(out: *mut u8, cap: usize) -> usize {
+    const MSG: &[u8] = b"hello from wzp-native\0";
+    if out.is_null() || cap == 0 {
+        return 0;
+    }
+    let n = MSG.len().min(cap);
+    unsafe {
+        core::ptr::copy_nonoverlapping(MSG.as_ptr(), out, n);
+        *out.add(n - 1) = 0;
+    }
+    n - 1
+}
+
+// ─── C++ Oboe bridge FFI ─────────────────────────────────────────────────
+
+#[repr(C)]
+struct WzpOboeConfig {
+    sample_rate: i32,
+    frames_per_burst: i32,
+    channel_count: i32,
+}
+
+#[repr(C)]
+struct WzpOboeRings {
+    capture_buf: *mut i16,
+    capture_capacity: i32,
+    capture_write_idx: *mut AtomicI32,
+    capture_read_idx: *mut AtomicI32,
+    playout_buf: *mut i16,
+    playout_capacity: i32,
+    playout_write_idx: *mut AtomicI32,
+    playout_read_idx: *mut AtomicI32,
+}
+
+// SAFETY: atomics synchronise producer/consumer; raw pointers are owned
+// by the AudioBackend singleton below whose lifetime covers all calls.
+unsafe impl Send for WzpOboeRings {}
+unsafe impl Sync for WzpOboeRings {}
+
+unsafe extern "C" {
+    fn wzp_oboe_start(config: *const WzpOboeConfig, rings: *const WzpOboeRings) -> i32;
+    fn wzp_oboe_stop();
+    fn wzp_oboe_capture_latency_ms() -> f32;
+    fn wzp_oboe_playout_latency_ms() -> f32;
+    fn wzp_oboe_is_running() -> i32;
+}
+
+// ─── SPSC ring buffer (shared with C++ via AtomicI32) ────────────────────
+
+/// 20 ms @ 48 kHz mono = 960 samples.
+const FRAME_SAMPLES: usize = 960;
+/// ~160 ms headroom at 48 kHz.
+const RING_CAPACITY: usize = 7680;
+
+struct RingBuffer {
+    buf: Vec<i16>,
+    capacity: usize,
+    write_idx: AtomicI32,
+    read_idx: AtomicI32,
+}
+
+// SAFETY: SPSC with atomic read/write cursors; producer and consumer
+// are always on different threads.
+unsafe impl Send for RingBuffer {}
+unsafe impl Sync for RingBuffer {}
+
+impl RingBuffer {
+    fn new(capacity: usize) -> Self {
+        Self {
+            buf: vec![0i16; capacity],
+            capacity,
+            write_idx: AtomicI32::new(0),
+            read_idx: AtomicI32::new(0),
+        }
+    }
+
+    fn available_read(&self) -> usize {
+        let w = self.write_idx.load(Ordering::Acquire);
+        let r = self.read_idx.load(Ordering::Relaxed);
+        let avail = w - r;
+        if avail < 0 { (avail + self.capacity as i32) as usize } else { avail as usize }
+    }
+
+    fn available_write(&self) -> usize {
+        self.capacity - 1 - self.available_read()
+    }
+
+    fn write(&self, data: &[i16]) -> usize {
+        let count = data.len().min(self.available_write());
+        if count == 0 {
+            return 0;
+        }
+        let mut w = self.write_idx.load(Ordering::Relaxed) as usize;
+        let cap = self.capacity;
+        let buf_ptr = self.buf.as_ptr() as *mut i16;
+        for sample in &data[..count] {
+            unsafe { *buf_ptr.add(w) = *sample; }
+            w += 1;
+            if w >= cap { w = 0; }
+        }
+        self.write_idx.store(w as i32, Ordering::Release);
+        count
+    }
+
+    fn read(&self, out: &mut [i16]) -> usize {
+        let count = out.len().min(self.available_read());
+        if count == 0 {
+            return 0;
+        }
+        let mut r = self.read_idx.load(Ordering::Relaxed) as usize;
+        let cap = self.capacity;
+        let buf_ptr = self.buf.as_ptr();
+        for slot in &mut out[..count] {
+            unsafe { *slot = *buf_ptr.add(r); }
+            r += 1;
+            if r >= cap { r = 0; }
+        }
+        self.read_idx.store(r as i32, Ordering::Release);
+        count
+    }
+
+    fn buf_ptr(&self) -> *mut i16 {
+        self.buf.as_ptr() as *mut i16
+    }
+    fn write_idx_ptr(&self) -> *mut AtomicI32 {
+        &self.write_idx as *const AtomicI32 as *mut AtomicI32
+    }
+    fn read_idx_ptr(&self) -> *mut AtomicI32 {
+        &self.read_idx as *const AtomicI32 as *mut AtomicI32
+    }
+}
+
+// ─── AudioBackend singleton ──────────────────────────────────────────────
+//
+// There is one global AudioBackend instance because Oboe's C++ side
+// holds its own singleton of the streams. The `Box::leak`'d statics own
+// the ring buffers for the lifetime of the process — dropping them while
+// Oboe is still running would cause use-after-free in the audio callback.
+
+use std::sync::OnceLock;
+
+struct AudioBackend {
+    capture: RingBuffer,
+    playout: RingBuffer,
+    started: std::sync::Mutex<bool>,
+    /// Per-write logging throttle counter for wzp_native_audio_write_playout.
+    playout_write_log_count: std::sync::atomic::AtomicU64,
+}
+
+static BACKEND: OnceLock<&'static AudioBackend> = OnceLock::new();
+
+fn backend() -> &'static AudioBackend {
+    BACKEND.get_or_init(|| {
+        Box::leak(Box::new(AudioBackend {
+            capture: RingBuffer::new(RING_CAPACITY),
+            playout: RingBuffer::new(RING_CAPACITY),
+            started: std::sync::Mutex::new(false),
+            playout_write_log_count: std::sync::atomic::AtomicU64::new(0),
+        }))
+    })
+}
+
+// ─── C FFI for wzp-desktop ───────────────────────────────────────────────
+
+/// Start the Oboe audio streams. Returns 0 on success, non-zero on error.
+/// Idempotent — calling while already running is a no-op that returns 0.
+#[unsafe(no_mangle)]
+pub extern "C" fn wzp_native_audio_start() -> i32 {
+    let b = backend();
+    let mut started = match b.started.lock() {
+        Ok(g) => g,
+        Err(_) => return -1,
+    };
+    if *started {
+        return 0;
+    }
+
+    let config = WzpOboeConfig {
+        sample_rate: 48_000,
+        frames_per_burst: FRAME_SAMPLES as i32,
+        channel_count: 1,
+    };
+    let rings = WzpOboeRings {
+        capture_buf: b.capture.buf_ptr(),
+        capture_capacity: b.capture.capacity as i32,
+        capture_write_idx: b.capture.write_idx_ptr(),
+        capture_read_idx: b.capture.read_idx_ptr(),
+        playout_buf: b.playout.buf_ptr(),
+        playout_capacity: b.playout.capacity as i32,
+        playout_write_idx: b.playout.write_idx_ptr(),
+        playout_read_idx: b.playout.read_idx_ptr(),
+    };
+    let ret = unsafe { wzp_oboe_start(&config, &rings) };
+    if ret != 0 {
+        return ret;
+    }
+    *started = true;
+    0
+}
+
+/// Stop Oboe. Idempotent. Safe to call from any thread.
+#[unsafe(no_mangle)]
+pub extern "C" fn wzp_native_audio_stop() {
+    let b = backend();
+    if let Ok(mut started) = b.started.lock() {
+        if *started {
+            unsafe { wzp_oboe_stop() };
+            *started = false;
+        }
+    }
+}
+
+/// Read captured PCM samples from the capture ring. Returns the number
+/// of `i16` samples actually copied into `out` (may be less than
+/// `out_len` if the ring is empty).
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn wzp_native_audio_read_capture(out: *mut i16, out_len: usize) -> usize {
+    if out.is_null() || out_len == 0 {
+        return 0;
+    }
+    let slice = unsafe { std::slice::from_raw_parts_mut(out, out_len) };
+    backend().capture.read(slice)
+}
+
+/// Write PCM samples into the playout ring. Returns the number of
+/// samples actually enqueued (may be less than `in_len` if the ring
+/// is nearly full — in practice the caller should pace to 20 ms
+/// frames and spin briefly if the ring is full).
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn wzp_native_audio_write_playout(input: *const i16, in_len: usize) -> usize {
+    if input.is_null() || in_len == 0 {
+        return 0;
+    }
+    let slice = unsafe { std::slice::from_raw_parts(input, in_len) };
+    let b = backend();
+    let before_w = b.playout.write_idx.load(std::sync::atomic::Ordering::Relaxed);
+    let before_r = b.playout.read_idx.load(std::sync::atomic::Ordering::Relaxed);
+    let written = b.playout.write(slice);
+    // First few writes: log ring state + sample range so we can compare what
+    // engine.rs hands us to what the C++ playout callback reads.
+    let first_writes = b.playout_write_log_count.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+    if first_writes < 3 || first_writes % 50 == 0 {
+        let (mut lo, mut hi, mut sumsq) = (i16::MAX, i16::MIN, 0i64);
+        for &s in slice.iter() {
+            if s < lo { lo = s; }
+            if s > hi { hi = s; }
+            sumsq += (s as i64) * (s as i64);
+        }
+        let rms = (sumsq as f64 / slice.len() as f64).sqrt() as i32;
+        let avail_w_after = b.playout.available_write();
+        let avail_r_after = b.playout.available_read();
+        let msg = format!(
+            "playout WRITE #{first_writes}: in_len={} written={} range=[{lo}..{hi}] rms={rms} before_w={before_w} before_r={before_r} avail_read_after={avail_r_after} avail_write_after={avail_w_after}",
+            slice.len(), written
+        );
+        unsafe {
+            android_log(msg.as_str());
+        }
+    }
+    written
+}
+
+// Minimal android logcat shim so we can print from the cdylib without pulling
+// in android_logger crate (which would add another dep that has to build with
+// cargo-ndk). Uses libc's __android_log_print via extern linkage.
+#[cfg(target_os = "android")]
+unsafe extern "C" {
+    fn __android_log_write(prio: i32, tag: *const u8, text: *const u8) -> i32;
+}
+
+#[cfg(target_os = "android")]
+unsafe fn android_log(msg: &str) {
+    // ANDROID_LOG_INFO = 4. Tag and text must be NUL-terminated.
+    let tag = b"wzp-native\0";
+    let mut buf = Vec::with_capacity(msg.len() + 1);
+    buf.extend_from_slice(msg.as_bytes());
+    buf.push(0);
+    unsafe { __android_log_write(4, tag.as_ptr(), buf.as_ptr()); }
+}
+
+#[cfg(not(target_os = "android"))]
+#[allow(dead_code)]
+unsafe fn android_log(_msg: &str) {}
+
+/// Current capture latency reported by Oboe, in milliseconds. Returns
+/// NaN / 0.0 if the stream isn't running.
+#[unsafe(no_mangle)]
+pub extern "C" fn wzp_native_audio_capture_latency_ms() -> f32 {
+    unsafe { wzp_oboe_capture_latency_ms() }
+}
+
+/// Current playout latency reported by Oboe, in milliseconds.
+#[unsafe(no_mangle)]
+pub extern "C" fn wzp_native_audio_playout_latency_ms() -> f32 {
+    unsafe { wzp_oboe_playout_latency_ms() }
+}
+
+/// Non-zero if both Oboe streams are currently running.
+#[unsafe(no_mangle)]
+pub extern "C" fn wzp_native_audio_is_running() -> i32 {
+    unsafe { wzp_oboe_is_running() }
+}

crates/wzp-proto/src/packet.rs

@@ -770,6 +770,29 @@ pub enum SignalMessage {
     CallRinging {
         call_id: String,
     },
+
+    // ── NAT reflection ("STUN for QUIC") ──────────────────────────────
+
+    /// Client → relay: "please tell me the source IP:port you see on
+    /// this connection". A QUIC-native replacement for classic STUN
+    /// that reuses the TLS-authenticated signal channel to the relay
+    /// instead of running a separate UDP reflection service on port
+    /// 3478. The relay answers with `ReflectResponse`.
+    ///
+    /// No payload — the relay already knows which connection the
+    /// request arrived on, and `connection.remote_address()` gives it
+    /// the exact source address (post-NAT) as observed from the
+    /// server side of the TLS session.
+    Reflect,
+
+    /// Relay → client: response to `Reflect`. Carries the socket
+    /// address the relay observes as the client's source for this
+    /// QUIC connection in `SocketAddr::to_string()` form — "a.b.c.d:p"
+    /// for IPv4, "[::1]:p" for IPv6. Clients parse it with
+    /// `SocketAddr::from_str`.
+    ReflectResponse {
+        observed_addr: String,
+    },
 }
 
 /// How the callee responds to a direct call.
@@ -908,6 +931,58 @@ mod tests {
         assert_eq!(packet.quality_report, decoded.quality_report);
     }
 
+    #[test]
+    fn reflect_serialize_roundtrip() {
+        // Reflect is a unit variant — the client sends it with no
+        // payload and the relay answers with the observed source addr.
+        let req = SignalMessage::Reflect;
+        let json = serde_json::to_string(&req).unwrap();
+        let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+        assert!(matches!(decoded, SignalMessage::Reflect));
+
+        // ReflectResponse carries a string — exercise both IPv4 and
+        // IPv6 shapes because SocketAddr::to_string uses [::1]:port
+        // for v6 and the client side has to parse that back.
+        for addr in ["192.0.2.17:4433", "[2001:db8::1]:4433", "127.0.0.1:54321"] {
+            let resp = SignalMessage::ReflectResponse {
+                observed_addr: addr.to_string(),
+            };
+            let json = serde_json::to_string(&resp).unwrap();
+            let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+            match decoded {
+                SignalMessage::ReflectResponse { observed_addr } => {
+                    assert_eq!(observed_addr, addr);
+                    // Must parse back to a SocketAddr cleanly.
+                    let _parsed: std::net::SocketAddr = observed_addr.parse()
+                        .expect("observed_addr must parse as SocketAddr");
+                }
+                _ => panic!("wrong variant after roundtrip"),
+            }
+        }
+    }
+
+    #[test]
+    fn reflect_backward_compat_with_existing_variants() {
+        // Adding Reflect/ReflectResponse at the end of the enum must
+        // not break JSON round-tripping of existing variants. Smoke-
+        // test a sample of the pre-existing ones.
+        let cases = vec![
+            SignalMessage::Ping { timestamp_ms: 12345 },
+            SignalMessage::Hold,
+            SignalMessage::Hangup { reason: HangupReason::Normal },
+            SignalMessage::CallRinging { call_id: "abcd".into() },
+        ];
+        for m in cases {
+            let json = serde_json::to_string(&m).unwrap();
+            let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+            // Discriminant equality proves variant tag survived.
+            assert_eq!(
+                std::mem::discriminant(&m),
+                std::mem::discriminant(&decoded)
+            );
+        }
+    }
+
     #[test]
     fn hold_unhold_serialize() {
         let hold = SignalMessage::Hold;

crates/wzp-relay/src/event_log.rs

@@ -5,7 +5,6 @@
 //! Use `wzp-analyzer` to correlate events across multiple relays.
 
 use std::path::PathBuf;
-use std::sync::Arc;
 
 use serde::Serialize;
 use tokio::sync::mpsc;

crates/wzp-relay/src/federation.rs

@@ -142,9 +142,6 @@ pub struct FederationManager {
     peer_links: Arc<Mutex<HashMap<String, PeerLink>>>,
     /// Dedup filter for incoming federation datagrams.
     dedup: Mutex<Deduplicator>,
-    /// Per-room seq counter for federation media delivered to local clients.
-    /// Ensures clients see monotonically increasing seq regardless of federation sender.
-    local_delivery_seq: std::sync::atomic::AtomicU16,
     /// JSONL event log for protocol analysis.
     event_log: EventLogger,
     /// Per-room rate limiters for inbound federation media.
@@ -172,7 +169,6 @@ impl FederationManager {
             metrics,
             peer_links: Arc::new(Mutex::new(HashMap::new())),
             dedup: Mutex::new(Deduplicator::new(DEDUP_WINDOW_SIZE)),
-            local_delivery_seq: std::sync::atomic::AtomicU16::new(0),
             event_log,
             rate_limiters: Mutex::new(HashMap::new()),
         }
@@ -296,7 +292,12 @@ impl FederationManager {
     /// Forward locally-generated media to all connected peers.
     /// For locally-originated media, we send to ALL peers (they decide whether to deliver).
     /// For forwarded media (multi-hop), handle_datagram filters by active_rooms.
-    pub async fn forward_to_peers(&self, room_name: &str, room_hash: &[u8; 8], media_data: &Bytes) {
+    ///
+    /// `_room_name` is kept in the signature for caller-site symmetry with
+    /// the other room-tagged helpers and for future per-room-name logging
+    /// or rate limiting; the body currently forwards on `room_hash` alone
+    /// because that's what the wire format carries.
+    pub async fn forward_to_peers(&self, _room_name: &str, room_hash: &[u8; 8], media_data: &Bytes) {
         let links = self.peer_links.lock().await;
         if links.is_empty() {
             return;
@@ -623,11 +624,20 @@ async fn run_federation_link(
         }
     };
 
-    // RTT monitor: periodically sample QUIC RTT for this peer
+    // RTT monitor: periodically sample QUIC RTT for this peer and push it
+    // into the `wzp_federation_peer_rtt_ms` gauge. The gauge is registered
+    // in metrics.rs but previously never received any samples — the task
+    // computed rtt_ms and dropped it on the floor, leaving the Grafana
+    // panel blank. Fixed as part of the workspace warning sweep.
     let rtt_task = async move {
         loop {
             tokio::time::sleep(Duration::from_secs(5)).await;
             let rtt_ms = rtt_transport.connection().stats().path.rtt.as_millis() as f64;
+            fm_rtt
+                .metrics
+                .federation_peer_rtt_ms
+                .with_label_values(&[&label_rtt])
+                .set(rtt_ms);
         }
     };
 

crates/wzp-relay/src/handshake.rs

@@ -94,9 +94,13 @@ pub async fn accept_handshake(
 }
 
 /// Select the best quality profile from those the caller supports.
-fn choose_profile(supported: &[QualityProfile]) -> QualityProfile {
+///
-    // Cap at GOOD (24k) for now — studio tiers (32k/48k/64k) not yet tested
+/// The `_supported` list is currently ignored — we hardcode GOOD (24k) until
-    // for federation reliability (large packets may exceed path MTU).
+/// studio tiers (32k/48k/64k) have been validated across federation (large
+/// packets may exceed path MTU and fragment in unpleasant ways). Once that's
+/// tested, the body should pick the highest supported profile ≤ the relay's
+/// configured ceiling.
+fn choose_profile(_supported: &[QualityProfile]) -> QualityProfile {
     QualityProfile::GOOD
 }
 

crates/wzp-relay/src/main.rs

@@ -13,7 +13,7 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use tokio::sync::Mutex;
-use tracing::{error, info, warn};
+use tracing::{debug, error, info, warn};
 
 use wzp_proto::{MediaTransport, SignalMessage};
 use wzp_relay::config::RelayConfig;
@@ -272,7 +272,7 @@ const BUILD_GIT_HASH: &str = env!("WZP_BUILD_HASH");
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    let CliResult { mut config, identity_path, config_file, config_needs_create } = parse_args();
+    let CliResult { config, identity_path, config_file, config_needs_create } = parse_args();
     tracing_subscriber::fmt().init();
     info!(version = BUILD_GIT_HASH, "wzp-relay build");
     rustls::crypto::ring::default_provider()
@@ -378,6 +378,31 @@ async fn main() -> anyhow::Result<()> {
     }
     let endpoint = wzp_transport::create_endpoint(config.listen_addr, Some(server_config))?;
 
+    // Compute the IP address we should advertise in CallSetup for direct
+    // calls. If the relay is bound to a specific IP, use it as-is; if bound
+    // to 0.0.0.0, use the trick of "connect" a UDP socket to an arbitrary
+    // external address and read its local_addr — the OS binds to whichever
+    // local interface IP would route packets to that destination, which is
+    // the primary outbound interface. This is the same IP clients on the
+    // LAN use to reach us.
+    let advertised_ip: std::net::IpAddr = {
+        let listen_ip = config.listen_addr.ip();
+        if !listen_ip.is_unspecified() {
+            listen_ip
+        } else {
+            // Probe via a dummy "connected" UDP socket. Never actually sends.
+            match std::net::UdpSocket::bind("0.0.0.0:0")
+                .and_then(|s| { s.connect("8.8.8.8:80").map(|_| s) })
+                .and_then(|s| s.local_addr())
+            {
+                Ok(a) if !a.ip().is_loopback() => a.ip(),
+                _ => std::net::IpAddr::from([127u8, 0, 0, 1]),
+            }
+        }
+    };
+    let advertised_addr_str = format!("{}:{}", advertised_ip, config.listen_addr.port());
+    info!(%advertised_addr_str, "relay advertised address for CallSetup");
+
     // Forward mode
     let remote_transport: Option<Arc<wzp_transport::QuinnTransport>> =
         if let Some(remote_addr) = config.remote_relay {
@@ -475,9 +500,19 @@ async fn main() -> anyhow::Result<()> {
     info!("Listening for connections...");
 
     loop {
-        let connection = match wzp_transport::accept(&endpoint).await {
+        // Pull the next Incoming off the queue. Deliberately do NOT await
-            Ok(conn) => conn,
+        // the QUIC handshake here — move that into the per-connection
-            Err(e) => { error!("accept: {e}"); continue; }
+        // spawned task below. Previously we used wzp_transport::accept
+        // which did both, which meant a single slow handshake would block
+        // the entire accept loop and prevent ALL subsequent connections
+        // from being processed. Surfaced as direct-call hangs where the
+        // callee's call-* connection never completes its QUIC handshake.
+        let incoming = match endpoint.accept().await {
+            Some(inc) => inc,
+            None => {
+                error!("endpoint.accept() returned None — endpoint closed");
+                break;
+            }
         };
 
         let remote_transport = remote_transport.clone();
@@ -493,9 +528,22 @@ async fn main() -> anyhow::Result<()> {
         let federation_mgr = federation_mgr.clone();
         let signal_hub = signal_hub.clone();
         let call_registry = call_registry.clone();
-        let listen_addr_str = config.listen_addr.to_string();
+        let advertised_addr_str = advertised_addr_str.clone();
+
+        let incoming_addr = incoming.remote_address();
+        info!(%incoming_addr, "accept queue: new Incoming, spawning handshake task");
 
         tokio::spawn(async move {
+            // Drive the QUIC handshake inside the spawned task so that
+            // slow or hung handshakes never block the outer accept loop.
+            let connection = match incoming.await {
+                Ok(c) => c,
+                Err(e) => {
+                    error!(%incoming_addr, "QUIC handshake failed: {e}");
+                    return;
+                }
+            };
+            info!(%incoming_addr, "QUIC handshake complete");
             let addr = connection.remote_address();
 
             let room_name = connection
@@ -718,7 +766,7 @@ async fn main() -> anyhow::Result<()> {
                     match transport.recv_signal().await {
                         Ok(Some(msg)) => {
                             match msg {
-                                SignalMessage::DirectCallOffer { ref target_fingerprint, ref call_id, ref caller_alias, .. } => {
+                                SignalMessage::DirectCallOffer { ref target_fingerprint, ref call_id, .. } => {
                                     let target_fp = target_fingerprint.clone();
                                     let call_id = call_id.clone();
 
@@ -793,22 +841,18 @@ async fn main() -> anyhow::Result<()> {
                                             let _ = hub.send_to(&peer_fp, &msg).await;
                                         }
 
-                                        // Send CallSetup to both parties
+                                        // Send CallSetup to both parties.
-                                        // Use the address the client connected to (their remote addr
+                                        //
-                                        // is our perspective, but we need our listen addr).
+                                        // BUG FIX: the previous version of this used `addr.ip()`
-                                        // Replace 0.0.0.0 with the client's destination IP.
+                                        // which is `connection.remote_address()` — the CLIENT'S
-                                        let relay_addr_for_setup = if listen_addr_str.starts_with("0.0.0.0:") {
+                                        // IP, not the relay's. So CallSetup told both parties to
-                                            let port = &listen_addr_str[8..];
+                                        // dial the answerer's own IP, which meant the caller was
-                                            // Use the local IP from the client's connection
+                                        // sending QUIC Initials into the callee's client (no
-                                            let local_ip = addr.ip();
+                                        // server listening there) and the callee was sending to
-                                            if local_ip.is_loopback() {
+                                        // itself. In both cases endpoint.connect() hung forever.
-                                                format!("127.0.0.1:{port}")
+                                        //
-                                            } else {
+                                        // Use the relay's precomputed advertised address instead.
-                                                format!("{local_ip}:{port}")
+                                        let relay_addr_for_setup = advertised_addr_str.clone();
-                                            }
-                                        } else {
-                                            listen_addr_str.clone()
-                                        };
                                         let setup = SignalMessage::CallSetup {
                                             call_id: call_id.clone(),
                                             room: room.clone(),
@@ -848,6 +892,31 @@ async fn main() -> anyhow::Result<()> {
                                     let _ = transport.send_signal(&SignalMessage::Pong { timestamp_ms }).await;
                                 }
 
+                                // QUIC-native NAT reflection ("STUN for QUIC").
+                                // The client asks "what source address do you
+                                // see for me?" and we reply with whatever
+                                // quinn reports as this connection's remote
+                                // address — i.e. the post-NAT public address
+                                // as observed from the server side of the TLS
+                                // session. Used by the P2P path to learn the
+                                // client's server-reflexive address without
+                                // running a separate STUN server. No auth or
+                                // rate-limit in Phase 1 — the client is
+                                // already TLS-authenticated by the time it
+                                // reaches this match arm.
+                                SignalMessage::Reflect => {
+                                    let observed_addr = addr.to_string();
+                                    if let Err(e) = transport.send_signal(
+                                        &SignalMessage::ReflectResponse {
+                                            observed_addr: observed_addr.clone(),
+                                        },
+                                    ).await {
+                                        warn!(%addr, error = %e, "reflect: failed to send response");
+                                    } else {
+                                        debug!(%addr, %observed_addr, "reflect: responded");
+                                    }
+                                }
+
                                 other => {
                                     warn!(%addr, "signal: unexpected message: {:?}", std::mem::discriminant(&other));
                                 }
@@ -1153,4 +1222,5 @@ async fn main() -> anyhow::Result<()> {
             }
         });
     }
+    Ok(())
 }

crates/wzp-relay/src/room.rs

@@ -10,7 +10,7 @@ use std::time::Duration;
 
 use bytes::Bytes;
 use tokio::sync::Mutex;
-use tracing::{debug, error, info, trace, warn};
+use tracing::{error, info, warn};
 
 use wzp_proto::packet::TrunkFrame;
 use wzp_proto::MediaTransport;
@@ -483,7 +483,6 @@ async fn run_participant_plain(
     );
 
     loop {
-        let recv_start = std::time::Instant::now();
         let pkt = match transport.recv_media().await {
             Ok(Some(pkt)) => pkt,
             Ok(None) => {
@@ -838,7 +837,7 @@ mod tests {
 
     #[test]
     fn room_join_leave() {
-        let mut mgr = RoomManager::new();
+        let mgr = RoomManager::new();
         assert_eq!(mgr.room_size("test"), 0);
         assert!(mgr.list().is_empty());
     }

crates/wzp-relay/src/signal_hub.rs

@@ -7,7 +7,7 @@ use std::collections::HashMap;
 use std::sync::Arc;
 use std::time::Instant;
 
-use tracing::{info, warn};
+use tracing::info;
 use wzp_proto::{MediaTransport, SignalMessage};
 use wzp_transport::QuinnTransport;
 
@@ -94,7 +94,7 @@ mod tests {
 
     #[test]
     fn register_unregister() {
-        let mut hub = SignalHub::new();
+        let hub = SignalHub::new();
         assert_eq!(hub.online_count(), 0);
         assert!(!hub.is_online("alice"));
 

crates/wzp-relay/tests/handshake_integration.rs

@@ -63,11 +63,11 @@ async fn handshake_succeeds() {
         accept_handshake(server_t.as_ref(), &callee_seed).await
     });
 
-    let caller_session = perform_handshake(client_transport.as_ref(), &caller_seed)
+    let caller_session = perform_handshake(client_transport.as_ref(), &caller_seed, None)
         .await
         .expect("perform_handshake should succeed");
 
-    let (callee_session, chosen_profile) = callee_handle
+    let (callee_session, chosen_profile, _caller_fp, _caller_alias) = callee_handle
         .await
         .expect("join callee task")
         .expect("accept_handshake should succeed");
@@ -124,11 +124,11 @@ async fn handshake_verifies_identity() {
         accept_handshake(server_t.as_ref(), &callee_seed).await
     });
 
-    let caller_session = perform_handshake(client_transport.as_ref(), &caller_seed)
+    let caller_session = perform_handshake(client_transport.as_ref(), &caller_seed, None)
         .await
         .expect("handshake must succeed even with different identities");
 
-    let (callee_session, _profile) = callee_handle
+    let (callee_session, _profile, _caller_fp, _caller_alias) = callee_handle
         .await
         .expect("join")
         .expect("accept_handshake must succeed");
@@ -183,7 +183,7 @@ async fn auth_then_handshake() {
         };
 
         // 2. Run the cryptographic handshake
-        let (session, profile) = accept_handshake(server_t.as_ref(), &callee_seed)
+        let (session, profile, _caller_fp, _caller_alias) = accept_handshake(server_t.as_ref(), &callee_seed)
             .await
             .expect("accept_handshake after auth");
 
@@ -199,7 +199,7 @@ async fn auth_then_handshake() {
         .await
         .expect("send AuthToken");
 
-    let caller_session = perform_handshake(client_transport.as_ref(), &caller_seed)
+    let caller_session = perform_handshake(client_transport.as_ref(), &caller_seed, None)
         .await
         .expect("perform_handshake after auth");
 
@@ -270,6 +270,7 @@ async fn handshake_rejects_bad_signature() {
         ephemeral_pub,
         signature,
         supported_profiles: vec![wzp_proto::QualityProfile::GOOD],
+        alias: None,
     };
 
     client_transport

crates/wzp-relay/tests/reflect.rs

@@ -0,0 +1,318 @@
+//! Integration tests for the "STUN for QUIC" reflect protocol
+//! (PRD: .taskmaster/docs/prd_reflect_over_quic.txt, Phase 1).
+//!
+//! We don't spin up the full relay binary — instead we exercise the
+//! same wire-level request/response dance with a mock relay loop
+//! that implements exactly the match arm added to
+//! `wzp-relay/src/main.rs`. This isolates the protocol test from the
+//! rest of the relay state (rooms, federation, call registry, ...).
+//!
+//! Three test cases:
+//!  1. `reflect_happy_path` — client sends `Reflect`, mock relay
+//!     replies with `ReflectResponse { observed_addr }`, client
+//!     parses it back to a `SocketAddr` and confirms the IP is
+//!     `127.0.0.1` and the port matches its own bound port.
+//!  2. `reflect_two_clients_distinct_ports` — two simultaneous
+//!     client connections on different ephemeral ports get back
+//!     different reflected ports, proving the relay uses
+//!     per-connection `remote_address` rather than a global.
+//!  3. `reflect_old_relay_times_out` — mock relay that *doesn't*
+//!     handle `Reflect`; client side times out in the expected
+//!     window and does not hang.
+//!
+//! The third test uses a `tokio::time::timeout` wrapper directly
+//! (the client-side `request_reflect` helper lives in
+//! `desktop/src-tauri/src/lib.rs` which isn't a library we can
+//! depend on from here, so we reproduce the timeout semantics
+//! inline).
+
+use std::net::{Ipv4Addr, SocketAddr};
+use std::sync::Arc;
+use std::time::Duration;
+
+use wzp_proto::{MediaTransport, SignalMessage};
+use wzp_transport::{client_config, create_endpoint, server_config, QuinnTransport};
+
+/// Spawn a minimal mock relay that loops over `recv_signal`,
+/// matches on `Reflect`, and responds with `ReflectResponse` using
+/// the remote_address observed for this connection. Mirrors the
+/// match arm in `crates/wzp-relay/src/main.rs`.
+async fn spawn_mock_relay_with_reflect(
+    server_transport: Arc<QuinnTransport>,
+) -> tokio::task::JoinHandle<()> {
+    tokio::spawn(async move {
+        // Observed remote address at the time the connection was
+        // accepted. Stable for the life of the connection under quinn's
+        // normal operation. This is exactly what the real relay does.
+        let observed = server_transport.connection().remote_address();
+        loop {
+            match server_transport.recv_signal().await {
+                Ok(Some(SignalMessage::Reflect)) => {
+                    let resp = SignalMessage::ReflectResponse {
+                        observed_addr: observed.to_string(),
+                    };
+                    // If the send fails the client has gone; just exit.
+                    if server_transport.send_signal(&resp).await.is_err() {
+                        break;
+                    }
+                }
+                Ok(Some(_other)) => {
+                    // Ignore anything else — not relevant to this test.
+                }
+                Ok(None) => break,
+                Err(_e) => break,
+            }
+        }
+    })
+}
+
+/// Spawn a mock relay that intentionally DOES NOT handle Reflect.
+/// Models a pre-Phase-1 relay — it keeps reading signal messages and
+/// logs them to stderr, but never produces a `ReflectResponse`.
+async fn spawn_mock_relay_without_reflect(
+    server_transport: Arc<QuinnTransport>,
+) -> tokio::task::JoinHandle<()> {
+    tokio::spawn(async move {
+        loop {
+            match server_transport.recv_signal().await {
+                Ok(Some(_msg)) => {
+                    // Deliberately do nothing. Old relay.
+                }
+                Ok(None) => break,
+                Err(_) => break,
+            }
+        }
+    })
+}
+
+/// Build an in-process QUIC client/server pair on loopback and
+/// return (client_transport, server_transport, endpoints). The
+/// endpoints tuple must be kept alive for the test duration.
+///
+/// `client_port_hint` of 0 means "let OS pick". Pass an explicit
+/// port to pin the client's source port (useful for the
+/// distinct-ports test).
+async fn connected_pair_with_port(
+    _client_port_hint: u16,
+) -> (Arc<QuinnTransport>, Arc<QuinnTransport>, (quinn::Endpoint, quinn::Endpoint)) {
+    let _ = rustls::crypto::ring::default_provider().install_default();
+
+    let (sc, _cert_der) = server_config();
+    let server_addr: SocketAddr = (Ipv4Addr::LOCALHOST, 0).into();
+    let server_ep = create_endpoint(server_addr, Some(sc)).expect("server endpoint");
+    let server_listen = server_ep.local_addr().expect("server local addr");
+
+    // Always bind the client to an ephemeral port — we'll read back
+    // the actual assigned port via `local_addr()` in the assertions.
+    let client_bind: SocketAddr = (Ipv4Addr::LOCALHOST, 0).into();
+    let client_ep = create_endpoint(client_bind, None).expect("client endpoint");
+
+    let server_ep_clone = server_ep.clone();
+    let accept_fut = tokio::spawn(async move {
+        let conn = wzp_transport::accept(&server_ep_clone).await.expect("accept");
+        Arc::new(QuinnTransport::new(conn))
+    });
+
+    let client_conn =
+        wzp_transport::connect(&client_ep, server_listen, "localhost", client_config())
+            .await
+            .expect("connect");
+    let client_transport = Arc::new(QuinnTransport::new(client_conn));
+    let server_transport = accept_fut.await.expect("join accept task");
+
+    (client_transport, server_transport, (server_ep, client_ep))
+}
+
+// -----------------------------------------------------------------------
+// Test 1: happy path — client learns its own port via Reflect
+// -----------------------------------------------------------------------
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn reflect_happy_path() {
+    let (client_transport, server_transport, (_server_ep, client_ep)) =
+        connected_pair_with_port(0).await;
+
+    // Grab the client's actual bound port so we can cross-check
+    // against the reflected response.
+    let client_port = client_ep
+        .local_addr()
+        .expect("client local addr")
+        .port();
+    assert_ne!(client_port, 0, "client must have a real bound port");
+
+    // Start the mock relay's reflect handler.
+    let _relay_handle = spawn_mock_relay_with_reflect(Arc::clone(&server_transport)).await;
+
+    // Client sends Reflect and awaits the response. The real
+    // request_reflect helper in desktop/src-tauri/src/lib.rs uses a
+    // oneshot channel driven off the spawned recv loop; here we just
+    // do it inline because there's no spawned loop yet in this test
+    // — this isolates the wire protocol from the client-side state
+    // machine.
+    client_transport
+        .send_signal(&SignalMessage::Reflect)
+        .await
+        .expect("send Reflect");
+
+    let resp = tokio::time::timeout(Duration::from_secs(2), client_transport.recv_signal())
+        .await
+        .expect("reflect response should arrive within 2s")
+        .expect("recv_signal ok")
+        .expect("some message");
+
+    let observed_addr = match resp {
+        SignalMessage::ReflectResponse { observed_addr } => observed_addr,
+        other => panic!("expected ReflectResponse, got {:?}", std::mem::discriminant(&other)),
+    };
+
+    let parsed: SocketAddr = observed_addr
+        .parse()
+        .expect("ReflectResponse.observed_addr must parse as SocketAddr");
+
+    // The relay should see the client on 127.0.0.1 (loopback in the
+    // test harness) and on the client's bound ephemeral port.
+    assert_eq!(parsed.ip().to_string(), "127.0.0.1");
+    assert_eq!(
+        parsed.port(),
+        client_port,
+        "reflected port must match the client's local_addr port"
+    );
+
+    drop(client_transport);
+    drop(server_transport);
+}
+
+// -----------------------------------------------------------------------
+// Test 2: two clients get DIFFERENT reflected ports
+// -----------------------------------------------------------------------
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn reflect_two_clients_distinct_ports() {
+    let _ = rustls::crypto::ring::default_provider().install_default();
+
+    // Shared server: one endpoint, two incoming accepts.
+    let (sc, _cert_der) = server_config();
+    let server_addr: SocketAddr = (Ipv4Addr::LOCALHOST, 0).into();
+    let server_ep = create_endpoint(server_addr, Some(sc)).expect("server endpoint");
+    let server_listen = server_ep.local_addr().expect("server local addr");
+
+    // Accept two clients in parallel.
+    let server_ep_a = server_ep.clone();
+    let accept_a = tokio::spawn(async move {
+        let conn = wzp_transport::accept(&server_ep_a).await.expect("accept A");
+        Arc::new(QuinnTransport::new(conn))
+    });
+    let server_ep_b = server_ep.clone();
+    let accept_b = tokio::spawn(async move {
+        let conn = wzp_transport::accept(&server_ep_b).await.expect("accept B");
+        Arc::new(QuinnTransport::new(conn))
+    });
+
+    // Client A
+    let client_ep_a = create_endpoint((Ipv4Addr::LOCALHOST, 0).into(), None).expect("ep A");
+    let conn_a =
+        wzp_transport::connect(&client_ep_a, server_listen, "localhost", client_config())
+            .await
+            .expect("connect A");
+    let client_a = Arc::new(QuinnTransport::new(conn_a));
+    let port_a = client_ep_a.local_addr().unwrap().port();
+
+    // Client B
+    let client_ep_b = create_endpoint((Ipv4Addr::LOCALHOST, 0).into(), None).expect("ep B");
+    let conn_b =
+        wzp_transport::connect(&client_ep_b, server_listen, "localhost", client_config())
+            .await
+            .expect("connect B");
+    let client_b = Arc::new(QuinnTransport::new(conn_b));
+    let port_b = client_ep_b.local_addr().unwrap().port();
+
+    assert_ne!(
+        port_a, port_b,
+        "preconditions: OS must assign two clients different ephemeral ports"
+    );
+
+    let server_a = accept_a.await.expect("join A");
+    let server_b = accept_b.await.expect("join B");
+
+    // Spawn a reflect handler for each server-side transport.
+    let _relay_a = spawn_mock_relay_with_reflect(Arc::clone(&server_a)).await;
+    let _relay_b = spawn_mock_relay_with_reflect(Arc::clone(&server_b)).await;
+
+    // Each client requests reflect concurrently.
+    let reflect_for = |t: Arc<QuinnTransport>| async move {
+        t.send_signal(&SignalMessage::Reflect).await.expect("send");
+        let resp = tokio::time::timeout(Duration::from_secs(2), t.recv_signal())
+            .await
+            .expect("timeout")
+            .expect("ok")
+            .expect("some");
+        match resp {
+            SignalMessage::ReflectResponse { observed_addr } => observed_addr,
+            _ => panic!("wrong variant"),
+        }
+    };
+
+    let (addr_a, addr_b) = tokio::join!(reflect_for(client_a.clone()), reflect_for(client_b.clone()));
+
+    let parsed_a: SocketAddr = addr_a.parse().unwrap();
+    let parsed_b: SocketAddr = addr_b.parse().unwrap();
+
+    assert_eq!(parsed_a.port(), port_a, "client A's reflected port");
+    assert_eq!(parsed_b.port(), port_b, "client B's reflected port");
+    assert_ne!(
+        parsed_a.port(),
+        parsed_b.port(),
+        "each client must see its own port, not a shared one"
+    );
+
+    drop(client_a);
+    drop(client_b);
+    drop(server_a);
+    drop(server_b);
+}
+
+// -----------------------------------------------------------------------
+// Test 3: old relay never answers — client times out cleanly
+// -----------------------------------------------------------------------
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn reflect_old_relay_times_out() {
+    let (client_transport, server_transport, _endpoints) =
+        connected_pair_with_port(0).await;
+
+    // Mock relay that ignores Reflect — simulates a pre-Phase-1 build.
+    let _relay_handle =
+        spawn_mock_relay_without_reflect(Arc::clone(&server_transport)).await;
+
+    client_transport
+        .send_signal(&SignalMessage::Reflect)
+        .await
+        .expect("send Reflect");
+
+    // 1100ms ceiling matches the 1s timeout baked into
+    // get_reflected_address plus a tiny bit of slack. If this
+    // regression ever fires it probably means recv_signal blocked
+    // longer than expected and the Tauri command would hang the UI.
+    let start = std::time::Instant::now();
+    let result =
+        tokio::time::timeout(Duration::from_millis(1100), client_transport.recv_signal()).await;
+    let elapsed = start.elapsed();
+
+    assert!(
+        result.is_err(),
+        "recv_signal must time out when the relay ignores Reflect"
+    );
+    assert!(
+        elapsed >= Duration::from_millis(1000),
+        "timeout fired too early ({:?})",
+        elapsed
+    );
+    assert!(
+        elapsed < Duration::from_millis(1200),
+        "timeout fired too late ({:?}), client would feel unresponsive",
+        elapsed
+    );
+
+    drop(client_transport);
+    drop(server_transport);
+}

crates/wzp-transport/src/lib.rs

@@ -27,3 +27,8 @@ pub use connection::{accept, connect, create_endpoint};
 pub use path_monitor::PathMonitor;
 pub use quic::QuinnTransport;
 pub use wzp_proto::{MediaTransport, PathQuality, TransportError};
+
+// Re-export the quinn Endpoint type so downstream crates (wzp-desktop) can
+// thread a shared endpoint between signaling and media connections without
+// needing to depend on quinn directly.
+pub use quinn::Endpoint;

crates/wzp-web/static/wasm/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "wzp-wasm",
+  "type": "module",
+  "description": "WarzonePhone WASM bindings — FEC (RaptorQ) + crypto (ChaCha20-Poly1305, X25519)",
+  "version": "0.1.0",
+  "files": [
+    "wzp_wasm_bg.wasm",
+    "wzp_wasm.js",
+    "wzp_wasm.d.ts"
+  ],
+  "main": "wzp_wasm.js",
+  "types": "wzp_wasm.d.ts",
+  "sideEffects": [
+    "./snippets/*"
+  ]
+}

crates/wzp-web/static/wasm/wzp_wasm.d.ts

@@ -0,0 +1,169 @@
+/* tslint:disable */
+/* eslint-disable */
+
+/**
+ * Symmetric encryption session using ChaCha20-Poly1305.
+ *
+ * Mirrors `wzp-crypto::session::ChaChaSession` for WASM.  Nonce derivation
+ * and key setup are identical so WASM and native peers interoperate.
+ */
+export class WzpCryptoSession {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * Decrypt a media payload with AAD.
+     *
+     * Returns plaintext on success, or throws on auth failure.
+     */
+    decrypt(header_aad: Uint8Array, ciphertext: Uint8Array): Uint8Array;
+    /**
+     * Encrypt a media payload with AAD (typically the 12-byte MediaHeader).
+     *
+     * Returns `ciphertext || poly1305_tag` (plaintext.len() + 16 bytes).
+     */
+    encrypt(header_aad: Uint8Array, plaintext: Uint8Array): Uint8Array;
+    /**
+     * Create from a 32-byte shared secret (output of `WzpKeyExchange.derive_shared_secret`).
+     */
+    constructor(shared_secret: Uint8Array);
+    /**
+     * Current receive sequence number (for diagnostics / UI stats).
+     */
+    recv_seq(): number;
+    /**
+     * Current send sequence number (for diagnostics / UI stats).
+     */
+    send_seq(): number;
+}
+
+export class WzpFecDecoder {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * Feed a received symbol.
+     *
+     * Returns the decoded block (concatenated original frames, unpadded) if
+     * enough symbols have been received to recover the block, or `undefined`.
+     */
+    add_symbol(block_id: number, symbol_idx: number, _is_repair: boolean, data: Uint8Array): Uint8Array | undefined;
+    /**
+     * Create a new FEC decoder.
+     *
+     * * `block_size` — expected number of source symbols per block.
+     * * `symbol_size` — padded byte size of each symbol (must match encoder).
+     */
+    constructor(block_size: number, symbol_size: number);
+}
+
+export class WzpFecEncoder {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * Add a source symbol (audio frame).
+     *
+     * Returns encoded packets (all source + repair) when the block is complete,
+     * or `undefined` if the block is still accumulating.
+     *
+     * Each returned packet carries the 3-byte header:
+     *   `[block_id][symbol_idx][is_repair]` followed by `symbol_size` bytes.
+     */
+    add_symbol(data: Uint8Array): Uint8Array | undefined;
+    /**
+     * Force-flush the current (possibly partial) block.
+     *
+     * Returns all source + repair symbols with headers, or empty vec if no
+     * symbols have been accumulated.
+     */
+    flush(): Uint8Array;
+    /**
+     * Create a new FEC encoder.
+     *
+     * * `block_size` — number of source symbols (audio frames) per FEC block.
+     * * `symbol_size` — padded byte size of each symbol (default 256).
+     */
+    constructor(block_size: number, symbol_size: number);
+}
+
+/**
+ * X25519 key exchange: generate ephemeral keypair and derive shared secret.
+ *
+ * Usage from JS:
+ * ```js
+ * const kx = new WzpKeyExchange();
+ * const ourPub = kx.public_key();         // Uint8Array(32)
+ * // ... send ourPub to peer, receive peerPub ...
+ * const secret = kx.derive_shared_secret(peerPub); // Uint8Array(32)
+ * const session = new WzpCryptoSession(secret);
+ * ```
+ */
+export class WzpKeyExchange {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * Derive a 32-byte session key from the peer's public key.
+     *
+     * Raw DH output is expanded via HKDF-SHA256 with info="warzone-session-key",
+     * matching `wzp-crypto::handshake::WarzoneKeyExchange::derive_session`.
+     */
+    derive_shared_secret(peer_public: Uint8Array): Uint8Array;
+    /**
+     * Generate a new random X25519 keypair.
+     */
+    constructor();
+    /**
+     * Our public key (32 bytes).
+     */
+    public_key(): Uint8Array;
+}
+
+export type InitInput = RequestInfo | URL | Response | BufferSource | WebAssembly.Module;
+
+export interface InitOutput {
+    readonly memory: WebAssembly.Memory;
+    readonly __wbg_wzpcryptosession_free: (a: number, b: number) => void;
+    readonly __wbg_wzpfecdecoder_free: (a: number, b: number) => void;
+    readonly __wbg_wzpfecencoder_free: (a: number, b: number) => void;
+    readonly __wbg_wzpkeyexchange_free: (a: number, b: number) => void;
+    readonly wzpcryptosession_decrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+    readonly wzpcryptosession_encrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+    readonly wzpcryptosession_new: (a: number, b: number) => [number, number, number];
+    readonly wzpcryptosession_recv_seq: (a: number) => number;
+    readonly wzpcryptosession_send_seq: (a: number) => number;
+    readonly wzpfecdecoder_add_symbol: (a: number, b: number, c: number, d: number, e: number, f: number) => [number, number];
+    readonly wzpfecdecoder_new: (a: number, b: number) => number;
+    readonly wzpfecencoder_add_symbol: (a: number, b: number, c: number) => [number, number];
+    readonly wzpfecencoder_flush: (a: number) => [number, number];
+    readonly wzpfecencoder_new: (a: number, b: number) => number;
+    readonly wzpkeyexchange_derive_shared_secret: (a: number, b: number, c: number) => [number, number, number, number];
+    readonly wzpkeyexchange_new: () => number;
+    readonly wzpkeyexchange_public_key: (a: number) => [number, number];
+    readonly __wbindgen_exn_store: (a: number) => void;
+    readonly __externref_table_alloc: () => number;
+    readonly __wbindgen_externrefs: WebAssembly.Table;
+    readonly __wbindgen_malloc: (a: number, b: number) => number;
+    readonly __externref_table_dealloc: (a: number) => void;
+    readonly __wbindgen_free: (a: number, b: number, c: number) => void;
+    readonly __wbindgen_start: () => void;
+}
+
+export type SyncInitInput = BufferSource | WebAssembly.Module;
+
+/**
+ * Instantiates the given `module`, which can either be bytes or
+ * a precompiled `WebAssembly.Module`.
+ *
+ * @param {{ module: SyncInitInput }} module - Passing `SyncInitInput` directly is deprecated.
+ *
+ * @returns {InitOutput}
+ */
+export function initSync(module: { module: SyncInitInput } | SyncInitInput): InitOutput;
+
+/**
+ * If `module_or_path` is {RequestInfo} or {URL}, makes a request and
+ * for everything else, calls `WebAssembly.instantiate` directly.
+ *
+ * @param {{ module_or_path: InitInput | Promise<InitInput> }} module_or_path - Passing `InitInput` directly is deprecated.
+ *
+ * @returns {Promise<InitOutput>}
+ */
+export default function __wbg_init (module_or_path?: { module_or_path: InitInput | Promise<InitInput> } | InitInput | Promise<InitInput>): Promise<InitOutput>;

crates/wzp-web/static/wasm/wzp_wasm_bg.wasm.d.ts

@@ -0,0 +1,27 @@
+/* tslint:disable */
+/* eslint-disable */
+export const memory: WebAssembly.Memory;
+export const __wbg_wzpcryptosession_free: (a: number, b: number) => void;
+export const __wbg_wzpfecdecoder_free: (a: number, b: number) => void;
+export const __wbg_wzpfecencoder_free: (a: number, b: number) => void;
+export const __wbg_wzpkeyexchange_free: (a: number, b: number) => void;
+export const wzpcryptosession_decrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+export const wzpcryptosession_encrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+export const wzpcryptosession_new: (a: number, b: number) => [number, number, number];
+export const wzpcryptosession_recv_seq: (a: number) => number;
+export const wzpcryptosession_send_seq: (a: number) => number;
+export const wzpfecdecoder_add_symbol: (a: number, b: number, c: number, d: number, e: number, f: number) => [number, number];
+export const wzpfecdecoder_new: (a: number, b: number) => number;
+export const wzpfecencoder_add_symbol: (a: number, b: number, c: number) => [number, number];
+export const wzpfecencoder_flush: (a: number) => [number, number];
+export const wzpfecencoder_new: (a: number, b: number) => number;
+export const wzpkeyexchange_derive_shared_secret: (a: number, b: number, c: number) => [number, number, number, number];
+export const wzpkeyexchange_new: () => number;
+export const wzpkeyexchange_public_key: (a: number) => [number, number];
+export const __wbindgen_exn_store: (a: number) => void;
+export const __externref_table_alloc: () => number;
+export const __wbindgen_externrefs: WebAssembly.Table;
+export const __wbindgen_malloc: (a: number, b: number) => number;
+export const __externref_table_dealloc: (a: number) => void;
+export const __wbindgen_free: (a: number, b: number, c: number) => void;
+export const __wbindgen_start: () => void;

desktop/.gitignore

@@ -0,0 +1,2 @@
+node_modules/
+dist/

desktop/.vite/deps/_metadata.json

@@ -0,0 +1,8 @@
+{
+  "hash": "9046c0bf",
+  "configHash": "ef0fc96f",
+  "lockfileHash": "d66891b1",
+  "browserHash": "8171ed59",
+  "optimized": {},
+  "chunks": {}
+}

desktop/.vite/deps/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

desktop/index.html

@@ -0,0 +1,251 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta
+      name="viewport"
+      content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=no, viewport-fit=cover"
+    />
+    <title>WarzonePhone</title>
+    <link rel="stylesheet" href="/src/style.css" />
+  </head>
+  <body>
+    <div id="app">
+      <!-- Connect screen -->
+      <div id="connect-screen">
+        <h1>WarzonePhone</h1>
+        <p class="subtitle">Encrypted Voice</p>
+        <div class="form">
+          <label>Relay
+            <button id="relay-selected" class="relay-selected" type="button">
+              <span id="relay-dot" class="dot"></span>
+              <span id="relay-label">Select relay...</span>
+              <span class="arrow">&#9881;</span>
+            </button>
+          </label>
+          <label>Room
+            <input id="room" type="text" value="general" />
+          </label>
+          <label>Alias
+            <input id="alias" type="text" placeholder="your name" />
+          </label>
+          <div class="form-row">
+            <label class="checkbox">
+              <input id="os-aec" type="checkbox" checked />
+              OS Echo Cancel
+            </label>
+            <button id="settings-btn-home" class="icon-btn" title="Settings (Cmd+,)">&#9881;</button>
+          </div>
+          <!-- Mode toggle -->
+          <div class="mode-toggle" style="display:flex;gap:8px;margin-bottom:8px;">
+            <button id="mode-room" class="mode-btn active" style="flex:1">Room</button>
+            <button id="mode-direct" class="mode-btn" style="flex:1">Direct Call</button>
+          </div>
+
+          <!-- Room mode (default) -->
+          <div id="room-mode">
+            <button id="connect-btn" class="primary">Connect</button>
+          </div>
+
+          <!-- Direct call mode -->
+          <div id="direct-mode" class="hidden">
+            <button id="register-btn" class="primary" style="background:#2196F3">Register on Relay</button>
+            <div id="direct-registered" class="hidden" style="margin-top:12px">
+              <div class="direct-registered-header">
+                <p style="color:var(--green);font-size:13px;margin:0">&#x2705; Registered — waiting for calls</p>
+                <button id="deregister-btn" class="secondary-btn small">Deregister</button>
+              </div>
+              <div id="incoming-call-panel" class="hidden" style="background:#1B5E20;padding:12px;border-radius:8px;margin:8px 0">
+                <p style="font-weight:bold;margin:0 0 4px 0">Incoming Call</p>
+                <p id="incoming-caller" style="font-size:12px;opacity:0.8;margin:0 0 8px 0">From: unknown</p>
+                <div style="display:flex;gap:8px">
+                  <button id="accept-call-btn" style="flex:1;background:var(--green);color:white;border:none;padding:8px;border-radius:6px;cursor:pointer">Accept</button>
+                  <button id="reject-call-btn" style="flex:1;background:var(--red);color:white;border:none;padding:8px;border-radius:6px;cursor:pointer">Reject</button>
+                </div>
+              </div>
+
+              <!-- Recent contacts -->
+              <div id="recent-contacts-section" class="hidden">
+                <div class="history-header">Recent contacts</div>
+                <div id="recent-contacts-list" class="history-list"></div>
+              </div>
+
+              <!-- Call history -->
+              <div id="call-history-section" class="hidden">
+                <div class="history-header">
+                  History
+                  <button id="clear-history-btn" class="link-btn">clear</button>
+                </div>
+                <div id="call-history-list" class="history-list"></div>
+              </div>
+
+              <label style="margin-top:8px">Call by fingerprint
+                <input id="target-fp" type="text" placeholder="xxxx:xxxx:xxxx:..." />
+              </label>
+              <button id="call-btn" class="primary" style="margin-top:8px">Call</button>
+              <p id="call-status-text" style="color:var(--yellow);font-size:13px;margin-top:4px"></p>
+            </div>
+          </div>
+
+          <p id="connect-error" class="error"></p>
+        </div>
+        <div class="identity-info">
+          <span id="my-identicon"></span>
+          <span id="my-fingerprint" class="fp-display"></span>
+        </div>
+        <div class="recent-rooms" id="recent-rooms"></div>
+      </div>
+
+      <!-- In-call screen -->
+      <div id="call-screen" class="hidden">
+        <div class="call-header">
+          <div class="call-header-row">
+            <div id="room-name" class="room-name"></div>
+            <button id="settings-btn-call" class="icon-btn small" title="Settings (Cmd+,)">&#9881;</button>
+          </div>
+          <div class="call-meta">
+            <span id="call-status" class="status-dot"></span>
+            <span id="call-timer" class="call-timer">0:00</span>
+          </div>
+        </div>
+        <div class="level-meter">
+          <div id="level-bar" class="level-bar-fill"></div>
+        </div>
+        <div id="participants" class="participants"></div>
+        <div class="controls">
+          <button id="mic-btn" class="control-btn" title="Toggle Mic (m)">
+            <span class="icon" id="mic-icon">Mic</span>
+          </button>
+          <button id="hangup-btn" class="control-btn hangup" title="Hang Up (q)">
+            <span class="icon">End</span>
+          </button>
+          <button id="spk-btn" class="control-btn" title="Toggle Speaker (s)">
+            <span class="icon" id="spk-icon">Spk</span>
+          </button>
+        </div>
+        <div id="stats" class="stats"></div>
+      </div>
+
+      <!-- Settings panel -->
+      <div id="settings-panel" class="hidden">
+        <div class="settings-card">
+          <div class="settings-header">
+            <h2>Settings</h2>
+            <button id="settings-close" class="icon-btn">&times;</button>
+          </div>
+          <div class="settings-section">
+            <h3>Connection</h3>
+            <label>Default Room
+              <input id="s-room" type="text" />
+            </label>
+            <label>Alias
+              <input id="s-alias" type="text" />
+            </label>
+          </div>
+          <div class="settings-section">
+            <h3>Audio</h3>
+            <div class="quality-control">
+              <div class="quality-header">
+                <span class="setting-label">QUALITY</span>
+                <span id="s-quality-label" class="quality-label">Auto</span>
+              </div>
+              <input id="s-quality" type="range" min="0" max="7" step="1" value="3" class="quality-slider" />
+              <div class="quality-ticks">
+                <span>64k</span>
+                <span>48k</span>
+                <span>32k</span>
+                <span>Auto</span>
+                <span>24k</span>
+                <span>6k</span>
+                <span>C2</span>
+                <span>1.2k</span>
+              </div>
+            </div>
+            <label class="checkbox">
+              <input id="s-os-aec" type="checkbox" />
+              OS Echo Cancellation (macOS VoiceProcessingIO)
+            </label>
+            <label class="checkbox">
+              <input id="s-agc" type="checkbox" checked />
+              Automatic Gain Control
+            </label>
+            <label class="checkbox">
+              <input id="s-dred-debug" type="checkbox" />
+              DRED debug logs (verbose, dev only)
+            </label>
+          </div>
+          <div class="settings-section">
+            <h3>Identity</h3>
+            <div class="setting-row">
+              <span class="setting-label">Fingerprint</span>
+              <span id="s-fingerprint" class="fp-display-large"></span>
+            </div>
+            <div class="setting-row">
+              <span class="setting-label">Identity file</span>
+              <span class="fp-display">~/.wzp/identity</span>
+            </div>
+          </div>
+          <div class="settings-section">
+            <h3>Network</h3>
+            <div class="setting-row">
+              <span class="setting-label">Public address</span>
+              <span id="s-reflected-addr" class="fp-display">(not queried)</span>
+              <button id="s-reflect-btn" class="secondary-btn">Detect</button>
+            </div>
+            <small style="color:var(--text-dim);display:block;margin-top:4px">
+              Asks the registered relay to echo back the IP:port it sees for this
+              connection (QUIC-native NAT reflection, replaces STUN).
+            </small>
+          </div>
+          <div class="settings-section">
+            <h3>Recent Rooms</h3>
+            <div id="s-recent-rooms" class="recent-rooms-list"></div>
+            <button id="s-clear-recent" class="secondary-btn">Clear History</button>
+          </div>
+          <button id="settings-save" class="primary">Save</button>
+        </div>
+      </div>
+
+      <!-- Manage Relays dialog -->
+      <div id="relay-dialog" class="hidden">
+        <div class="settings-card relay-dialog-card">
+          <div class="settings-header">
+            <h2>Manage Relays</h2>
+            <button id="relay-dialog-close" class="icon-btn">&times;</button>
+          </div>
+          <div id="relay-dialog-list" class="relay-dialog-list"></div>
+          <div class="relay-add-row">
+            <div class="relay-add-inputs">
+              <input id="relay-add-name" type="text" placeholder="Name" />
+              <input id="relay-add-addr" type="text" placeholder="host:port" />
+            </div>
+            <button id="relay-add-btn" class="primary">Add Relay</button>
+          </div>
+        </div>
+      </div>
+      <!-- Key changed warning dialog -->
+      <div id="key-warning" class="hidden">
+        <div class="settings-card key-warning-card">
+          <div class="key-warning-icon">&#9888;</div>
+          <h2>Server Key Changed</h2>
+          <p class="key-warning-text">The relay's identity has changed since you last connected. This usually happens when the server was restarted, but could also indicate a security issue.</p>
+          <div class="key-warning-fps">
+            <div class="key-fp-row">
+              <span class="key-fp-label">Previously known</span>
+              <code id="kw-old-fp" class="key-fp"></code>
+            </div>
+            <div class="key-fp-row">
+              <span class="key-fp-label">New key</span>
+              <code id="kw-new-fp" class="key-fp"></code>
+            </div>
+          </div>
+          <div class="key-warning-actions">
+            <button id="kw-accept" class="primary">Accept New Key</button>
+            <button id="kw-cancel" class="secondary-btn">Cancel</button>
+          </div>
+        </div>
+      </div>
+    </div>
+    <script type="module" src="/src/main.ts"></script>
+  </body>
+</html>

desktop/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "wzp-desktop",
+  "private": true,
+  "version": "0.1.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "tauri": "tauri"
+  },
+  "dependencies": {
+    "@tauri-apps/api": "^2"
+  },
+  "devDependencies": {
+    "typescript": "^5",
+    "vite": "^6",
+    "@tauri-apps/cli": "^2"
+  }
+}

desktop/src-tauri/Cargo.toml

@@ -0,0 +1,107 @@
+[package]
+name = "wzp-desktop"
+version = "0.1.0"
+edition = "2024"
+description = "WarzonePhone Desktop — encrypted VoIP client"
+default-run = "wzp-desktop"
+
+# Library target — required for Tauri mobile (Android/iOS link the app as a cdylib)
+# and also used by the desktop binary below.
+#
+# `staticlib` was DROPPED from crate-type because rust-lang/rust#104707
+# documents that having staticlib alongside cdylib leaks non-exported
+# symbols from staticlibs into the cdylib. Bionic's private `__init_tcb`
+# / `pthread_create` symbols end up bound LOCALLY inside our .so instead
+# of resolved dynamically against libc.so at dlopen time — which crashes
+# at launch as soon as tao tries to std::thread::spawn() from the JNI
+# onCreate callback. The legacy wzp-android crate uses ["cdylib", "rlib"]
+# and runs fine on the same phone with the same NDK + Rust toolchain.
+#
+# iOS Tauri builds that actually need staticlib can re-add it behind a
+# target cfg if we ever ship on iOS.
+[lib]
+name = "wzp_desktop_lib"
+crate-type = ["cdylib", "rlib"]
+
+[[bin]]
+name = "wzp-desktop"
+path = "src/main.rs"
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+# cc is no longer needed — all C++ moved to crates/wzp-native (built with
+# cargo-ndk and loaded via libloading at runtime). wzp-desktop's .so on
+# Android is now pure Rust.
+
+[dependencies]
+tauri = { version = "2", features = [] }
+tauri-plugin-shell = "2"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+tokio = { version = "1", features = ["full"] }
+tracing = "0.1"
+tracing-subscriber = "0.3"
+anyhow = "1"
+rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
+
+# WarzonePhone crates — protocol layer is platform-independent
+wzp-proto = { path = "../../crates/wzp-proto" }
+wzp-codec = { path = "../../crates/wzp-codec" }
+wzp-fec = { path = "../../crates/wzp-fec" }
+wzp-crypto = { path = "../../crates/wzp-crypto" }
+wzp-transport = { path = "../../crates/wzp-transport" }
+
+# wzp-client pulls in CPAL on every desktop target and, additionally on
+# macOS, VoiceProcessingIO (coreaudio-rs behind the "vpio" feature). The
+# vpio feature MUST NOT be enabled on Windows / Linux because coreaudio-rs
+# is Apple-framework-only and will fail to build. Task #24 will add a
+# matching Windows Voice Capture DSP path behind its own feature; until
+# then, Windows desktops use plain CPAL with AEC disabled.
+
+# macOS: CPAL + VoiceProcessingIO (hardware AEC via Core Audio).
+[target.'cfg(target_os = "macos")'.dependencies]
+wzp-client = { path = "../../crates/wzp-client", features = ["audio", "vpio"] }
+
+# Windows: CPAL for playback + direct WASAPI for capture with OS-level
+# AEC (AudioCategory_Communications). The wzp-client `windows-aec`
+# feature swaps the default CPAL AudioCapture for a WASAPI one that
+# opens the mic under AudioCategory_Communications, turning on Windows's
+# communications audio processing chain (AEC, NS, AGC). The reference
+# signal for AEC is the system render mix, so echo from our CPAL
+# playback is cancelled automatically without extra plumbing.
+[target.'cfg(target_os = "windows")'.dependencies]
+wzp-client = { path = "../../crates/wzp-client", features = ["audio", "windows-aec"] }
+
+# Linux: CPAL playback+capture baseline. AEC is enabled via the top-level
+# `linux-aec` feature in wzp-desktop, which forwards to wzp-client/linux-aec.
+# Keeping it opt-in at the wzp-desktop level (rather than forcing it always
+# on here) lets `cargo tauri build` produce two variants from the same
+# source tree — a noAEC baseline and an AEC build — by toggling the feature
+# at build time: `cargo tauri build -- --features wzp-desktop/linux-aec`.
+[target.'cfg(target_os = "linux")'.dependencies]
+wzp-client = { path = "../../crates/wzp-client", features = ["audio"] }
+
+# Android: no CPAL, no vpio — audio goes through the standalone wzp-native
+# cdylib that we dlopen via libloading at runtime. See the wzp_native
+# module in src/.
+[target.'cfg(target_os = "android")'.dependencies]
+wzp-client = { path = "../../crates/wzp-client", default-features = false }
+# libloading: runtime dlopen of libwzp_native.so — the standalone cdylib
+# crate that owns all C++ (Oboe bridge). Keeps wzp-desktop's .so free of
+# any C/C++ static archives that would otherwise leak bionic's internal
+# pthread_create into our cdylib and trigger the __init_tcb crash.
+libloading = "0.8"
+# jni + ndk-context: called from android_audio.rs to invoke
+# AudioManager.setSpeakerphoneOn on the JVM side at runtime, so the
+# Oboe playout stream (opened with Usage::VoiceCommunication) can route
+# between earpiece and loud speaker without restarting.
+jni = "0.21"
+ndk-context = "0.1"
+
+[features]
+default = ["custom-protocol"]
+custom-protocol = ["tauri/custom-protocol"]
+# linux-aec: forwards to wzp-client/linux-aec so `cargo tauri build -- --features
+# wzp-desktop/linux-aec` enables the WebRTC AEC3 backend on Linux. No-op on
+# other targets because wzp-client/linux-aec is itself cfg(target_os = "linux").
+linux-aec = ["wzp-client/linux-aec"]

desktop/src-tauri/Info.plist

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <!--
+      Custom Info.plist keys merged into the bundled WarzonePhone.app by
+      tauri-bundler. The base Info.plist (CFBundleIdentifier, version,
+      etc.) is generated from tauri.conf.json — only put *additional*
+      keys here.
+
+      NSMicrophoneUsageDescription is required by macOS TCC for any
+      app that opens an audio input unit. Without this string the OS
+      silently denies CoreAudio capture (input callbacks return zeros)
+      and the app never appears in System Settings → Privacy &
+      Security → Microphone. This was the root cause of the desktop
+      mic regression where phones could not hear the desktop client.
+    -->
+    <key>NSMicrophoneUsageDescription</key>
+    <string>WarzonePhone needs microphone access to transmit your voice during calls.</string>
+</dict>
+</plist>

desktop/src-tauri/build.rs

@@ -0,0 +1,26 @@
+use std::process::Command;
+
+fn main() {
+    // Capture short git hash so the running app can prove which build it is.
+    // Falls back to "unknown" if git isn't available (e.g. when building from
+    // a tarball without a .git dir).
+    let git_hash = Command::new("git")
+        .args(["rev-parse", "--short", "HEAD"])
+        .output()
+        .ok()
+        .filter(|o| o.status.success())
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".into());
+
+    println!("cargo:rustc-env=WZP_GIT_HASH={git_hash}");
+    println!("cargo:rerun-if-changed=../../.git/HEAD");
+    println!("cargo:rerun-if-changed=../../.git/refs/heads");
+
+    // No cc::Build of ANY kind on Android — all C++ lives in the standalone
+    // `wzp-native` crate which is built separately with cargo-ndk and loaded
+    // via libloading at runtime. See docs/incident-tauri-android-init-tcb.md
+    // for why this split exists.
+
+    tauri_build::build()
+}

desktop/src-tauri/capabilities/default.json

@@ -0,0 +1,26 @@
+{
+  "$schema": "../gen/schemas/desktop-schema.json",
+  "identifier": "default",
+  "description": "Default capability — grants core APIs (events, path, window, app, clipboard) to the main window on every platform we ship to.",
+  "windows": ["main"],
+  "platforms": [
+    "linux",
+    "macOS",
+    "windows",
+    "android",
+    "iOS"
+  ],
+  "permissions": [
+    "core:default",
+    "core:event:default",
+    "core:event:allow-listen",
+    "core:event:allow-unlisten",
+    "core:event:allow-emit",
+    "core:event:allow-emit-to",
+    "core:path:default",
+    "core:window:default",
+    "core:app:default",
+    "core:webview:default",
+    "shell:default"
+  ]
+}

desktop/src-tauri/gen/android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
+    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
+    <uses-feature android:name="android.hardware.microphone" android:required="true" />
+
+    <!-- AndroidTV support -->
+    <uses-feature android:name="android.software.leanback" android:required="false" />
+
+    <application
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:theme="@style/Theme.wzp_desktop"
+        android:usesCleartextTraffic="${usesCleartextTraffic}">
+        <activity
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|smallestScreenSize|screenLayout|uiMode"
+            android:launchMode="singleTask"
+            android:label="@string/main_activity_title"
+            android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+                <!-- AndroidTV support -->
+                <category android:name="android.intent.category.LEANBACK_LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+        <provider
+          android:name="androidx.core.content.FileProvider"
+          android:authorities="${applicationId}.fileprovider"
+          android:exported="false"
+          android:grantUriPermissions="true">
+          <meta-data
+            android:name="android.support.FILE_PROVIDER_PATHS"
+            android:resource="@xml/file_paths" />
+        </provider>
+    </application>
+</manifest>

desktop/src-tauri/gen/android/app/src/main/java/com/wzp/desktop/MainActivity.kt

@@ -0,0 +1,101 @@
+package com.wzp.desktop
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.media.AudioManager
+import android.os.Bundle
+import android.util.Log
+import androidx.activity.enableEdgeToEdge
+import androidx.core.app.ActivityCompat
+import androidx.core.content.ContextCompat
+
+class MainActivity : TauriActivity() {
+  companion object {
+    private const val TAG = "WzpMainActivity"
+    private const val AUDIO_PERMISSIONS_REQUEST = 4242
+    private val REQUIRED_AUDIO_PERMISSIONS = arrayOf(
+      Manifest.permission.RECORD_AUDIO,
+      Manifest.permission.MODIFY_AUDIO_SETTINGS
+    )
+  }
+
+  override fun onCreate(savedInstanceState: Bundle?) {
+    enableEdgeToEdge()
+    super.onCreate(savedInstanceState)
+
+    // Request RECORD_AUDIO early so Oboe (inside libwzp_native.so) can open
+    // the AAudio input stream without silently failing. The grant is
+    // persisted, so after the first launch the dialog no longer appears.
+    // MODIFY_AUDIO_SETTINGS is needed to switch AudioManager mode + speaker.
+    val needsRequest = REQUIRED_AUDIO_PERMISSIONS.any {
+      ContextCompat.checkSelfPermission(this, it) != PackageManager.PERMISSION_GRANTED
+    }
+    if (needsRequest) {
+      Log.i(TAG, "requesting audio permissions")
+      ActivityCompat.requestPermissions(this, REQUIRED_AUDIO_PERMISSIONS, AUDIO_PERMISSIONS_REQUEST)
+    } else {
+      Log.i(TAG, "audio permissions already granted")
+      configureAudioForCall()
+    }
+  }
+
+  override fun onRequestPermissionsResult(
+    requestCode: Int,
+    permissions: Array<String>,
+    grantResults: IntArray
+  ) {
+    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
+    if (requestCode == AUDIO_PERMISSIONS_REQUEST) {
+      val allGranted = grantResults.isNotEmpty() &&
+        grantResults.all { it == PackageManager.PERMISSION_GRANTED }
+      Log.i(TAG, "audio permissions result: allGranted=$allGranted grants=${grantResults.toList()}")
+      if (allGranted) {
+        configureAudioForCall()
+      }
+    }
+  }
+
+  /**
+   * Put the phone into VoIP call mode with handset (earpiece) as the
+   * default output. The Oboe playout stream is opened with
+   * Usage::VoiceCommunication which honours this routing, so:
+   *
+   *   MODE_IN_COMMUNICATION + speakerphoneOn=false  → earpiece (handset)
+   *   MODE_IN_COMMUNICATION + speakerphoneOn=true   → loudspeaker
+   *   MODE_IN_COMMUNICATION + bluetoothScoOn=true   → bluetooth headset
+   *
+   * The speaker/handset/BT toggle itself is wired up via the Tauri
+   * command `set_speakerphone(on)` in a follow-up build. For now the
+   * default is handset, matching the user's stated preference.
+   *
+   * STREAM_VOICE_CALL volume is cranked to max since the in-call volume
+   * slider is separate from media volume on most devices.
+   */
+  private fun configureAudioForCall() {
+    try {
+      val am = getSystemService(Context.AUDIO_SERVICE) as AudioManager
+      Log.i(TAG, "audio state before: mode=${am.mode} speaker=${am.isSpeakerphoneOn} " +
+        "voiceVol=${am.getStreamVolume(AudioManager.STREAM_VOICE_CALL)}/" +
+        "${am.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL)} " +
+        "musicVol=${am.getStreamVolume(AudioManager.STREAM_MUSIC)}/" +
+        "${am.getStreamMaxVolume(AudioManager.STREAM_MUSIC)}")
+
+      am.mode = AudioManager.MODE_IN_COMMUNICATION
+      am.isSpeakerphoneOn = false   // default: handset / earpiece
+
+      // Crank both voice-call and music volumes so nothing silent slips
+      // through regardless of which stream actually ends up driving.
+      val maxVoice = am.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL)
+      am.setStreamVolume(AudioManager.STREAM_VOICE_CALL, maxVoice, 0)
+      val maxMusic = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC)
+      am.setStreamVolume(AudioManager.STREAM_MUSIC, maxMusic, 0)
+
+      Log.i(TAG, "audio state after: mode=${am.mode} speaker=${am.isSpeakerphoneOn} " +
+        "voiceVol=${am.getStreamVolume(AudioManager.STREAM_VOICE_CALL)}/$maxVoice " +
+        "musicVol=${am.getStreamVolume(AudioManager.STREAM_MUSIC)}/$maxMusic")
+    } catch (e: Throwable) {
+      Log.e(TAG, "configureAudioForCall failed: ${e.message}", e)
+    }
+  }
+}

desktop/src-tauri/gen/schemas/capabilities.json

@@ -0,0 +1 @@
+{"default":{"identifier":"default","description":"Default capability — grants core APIs (events, path, window, app, clipboard) to the main window on every platform we ship to.","local":true,"windows":["main"],"permissions":["core:default","core:event:default","core:event:allow-listen","core:event:allow-unlisten","core:event:allow-emit","core:event:allow-emit-to","core:path:default","core:window:default","core:app:default","core:webview:default","shell:default"],"platforms":["linux","macOS","windows","android","iOS"]}}

desktop/src-tauri/src/android_audio.rs

@@ -0,0 +1,98 @@
+//! Runtime bridge to Android's `AudioManager` for in-call audio routing.
+//!
+//! We own a quinn+Oboe VoIP pipeline entirely from Rust, but routing the
+//! playout stream between earpiece / loudspeaker / Bluetooth headset has to
+//! happen at the JVM level because those toggles are AudioManager-only.
+//! This module uses the global JavaVM handle that `ndk_context` exposes
+//! (populated by Tauri's mobile runtime) + the `jni` crate to reach into
+//! the Android framework without needing a Tauri plugin.
+//!
+//! All callers must be inside an Android target (`#[cfg(target_os = "android")]`).
+
+#![cfg(target_os = "android")]
+
+use jni::objects::{JObject, JString, JValue};
+use jni::JavaVM;
+
+/// Grab the JavaVM + current Activity from the ndk_context that Tauri's
+/// mobile runtime sets up at process startup.
+fn jvm_and_activity() -> Result<(JavaVM, JObject<'static>), String> {
+    let ctx = ndk_context::android_context();
+    let vm_ptr = ctx.vm() as *mut jni::sys::JavaVM;
+    if vm_ptr.is_null() {
+        return Err("ndk_context: JavaVM pointer is null".into());
+    }
+    let vm = unsafe { JavaVM::from_raw(vm_ptr) }
+        .map_err(|e| format!("JavaVM::from_raw: {e}"))?;
+    let activity_ptr = ctx.context() as jni::sys::jobject;
+    if activity_ptr.is_null() {
+        return Err("ndk_context: activity pointer is null".into());
+    }
+    // SAFETY: ndk_context guarantees the pointer lives for the process
+    // lifetime; we wrap it as a JObject<'static> for convenience.
+    let activity: JObject<'static> = unsafe { JObject::from_raw(activity_ptr) };
+    Ok((vm, activity))
+}
+
+/// Get Android's `AudioManager` via `activity.getSystemService("audio")`.
+fn audio_manager<'local>(
+    env: &mut jni::AttachGuard<'local>,
+    activity: &JObject<'local>,
+) -> Result<JObject<'local>, String> {
+    let svc_name: JString<'local> = env
+        .new_string("audio")
+        .map_err(|e| format!("new_string(audio): {e}"))?;
+    let am = env
+        .call_method(
+            activity,
+            "getSystemService",
+            "(Ljava/lang/String;)Ljava/lang/Object;",
+            &[JValue::Object(&svc_name)],
+        )
+        .and_then(|v| v.l())
+        .map_err(|e| format!("getSystemService(audio): {e}"))?;
+    if am.is_null() {
+        return Err("getSystemService returned null".into());
+    }
+    Ok(am)
+}
+
+/// Switch between loud speaker (`true`) and earpiece/handset (`false`).
+///
+/// Calls `AudioManager.setSpeakerphoneOn(on)` on the JVM. Requires that
+/// the audio mode is already `MODE_IN_COMMUNICATION` — MainActivity.kt
+/// sets this at startup, so by the time a call is up this is always true.
+pub fn set_speakerphone(on: bool) -> Result<(), String> {
+    let (vm, activity) = jvm_and_activity()?;
+    let mut env = vm
+        .attach_current_thread()
+        .map_err(|e| format!("attach_current_thread: {e}"))?;
+    let am = audio_manager(&mut env, &activity)?;
+
+    env.call_method(
+        &am,
+        "setSpeakerphoneOn",
+        "(Z)V",
+        &[JValue::Bool(if on { 1 } else { 0 })],
+    )
+    .map_err(|e| format!("setSpeakerphoneOn({on}): {e}"))?;
+
+    tracing::info!(on, "AudioManager.setSpeakerphoneOn");
+    Ok(())
+}
+
+/// Query the current speakerphone state. Returns true if routing is on the
+/// loud speaker, false if on earpiece / BT headset / wired headset.
+pub fn is_speakerphone_on() -> Result<bool, String> {
+    let (vm, activity) = jvm_and_activity()?;
+    let mut env = vm
+        .attach_current_thread()
+        .map_err(|e| format!("attach_current_thread: {e}"))?;
+    let am = audio_manager(&mut env, &activity)?;
+
+    let on = env
+        .call_method(&am, "isSpeakerphoneOn", "()Z", &[])
+        .and_then(|v| v.z())
+        .map_err(|e| format!("isSpeakerphoneOn: {e}"))?;
+    Ok(on)
+}

desktop/src-tauri/src/history.rs

@@ -0,0 +1,180 @@
+//! Call history store.
+//!
+//! Keeps a rolling JSON file of the last N direct-call events so the UI can
+//! show "recent contacts" + "call history with callback buttons" on the
+//! direct-call screen. Storage lives in `<APP_DATA_DIR>/call_history.json`
+//! alongside the identity file. The file is read lazily on first access and
+//! cached in an RwLock behind a OnceLock.
+//!
+//! This is a v1 — no duration tracking yet, entries are logged at the
+//! moment the direction is decided (placed / received / missed).
+
+use std::path::PathBuf;
+use std::sync::{OnceLock, RwLock};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use serde::{Deserialize, Serialize};
+
+/// Maximum number of history entries we keep. Older ones are pruned FIFO.
+const MAX_ENTRIES: usize = 200;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum CallDirection {
+    /// Local user placed the call.
+    Placed,
+    /// Remote user called and local user answered.
+    Received,
+    /// Remote user called but local user did not answer (rejected or
+    /// missed entirely — the UI treats these identically).
+    Missed,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CallHistoryEntry {
+    pub call_id: String,
+    pub peer_fp: String,
+    pub peer_alias: Option<String>,
+    pub direction: CallDirection,
+    /// Seconds since UNIX epoch, UTC.
+    pub timestamp_unix: u64,
+}
+
+// ─── In-process store (loaded from disk once) ─────────────────────────────
+
+static STORE: OnceLock<RwLock<Vec<CallHistoryEntry>>> = OnceLock::new();
+
+fn store() -> &'static RwLock<Vec<CallHistoryEntry>> {
+    STORE.get_or_init(|| RwLock::new(load_from_disk()))
+}
+
+fn history_path() -> PathBuf {
+    crate::APP_DATA_DIR
+        .get()
+        .cloned()
+        .unwrap_or_else(|| {
+            let home = std::env::var("HOME").unwrap_or_else(|_| ".".into());
+            PathBuf::from(home).join(".wzp")
+        })
+        .join("call_history.json")
+}
+
+fn load_from_disk() -> Vec<CallHistoryEntry> {
+    let path = history_path();
+    let Ok(bytes) = std::fs::read(&path) else {
+        return Vec::new();
+    };
+    serde_json::from_slice::<Vec<CallHistoryEntry>>(&bytes)
+        .inspect_err(|e| tracing::warn!(path = %path.display(), error = %e, "call_history.json parse failed"))
+        .unwrap_or_default()
+}
+
+fn save_to_disk(entries: &[CallHistoryEntry]) {
+    let path = history_path();
+    if let Some(parent) = path.parent() {
+        let _ = std::fs::create_dir_all(parent);
+    }
+    let Ok(json) = serde_json::to_vec_pretty(entries) else { return };
+    // Atomic write via temp file + rename so a crash mid-write doesn't
+    // leave us with a half-file on disk.
+    let tmp = path.with_extension("json.tmp");
+    if std::fs::write(&tmp, &json).is_ok() {
+        let _ = std::fs::rename(&tmp, &path);
+    }
+}
+
+fn now_unix() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_secs())
+        .unwrap_or(0)
+}
+
+// ─── Public API ───────────────────────────────────────────────────────────
+
+/// Append a new entry to the store and persist to disk. Trims the store to
+/// `MAX_ENTRIES` after insertion.
+pub fn log(
+    call_id: String,
+    peer_fp: String,
+    peer_alias: Option<String>,
+    direction: CallDirection,
+) {
+    tracing::info!(
+        %call_id, %peer_fp, ?direction,
+        alias = ?peer_alias,
+        "history::log"
+    );
+    let entry = CallHistoryEntry {
+        call_id: call_id.clone(),
+        peer_fp,
+        peer_alias,
+        direction,
+        timestamp_unix: now_unix(),
+    };
+    let mut guard = store().write().unwrap();
+    // If an entry for this call_id already exists, update it in-place
+    // rather than appending a duplicate. Protects against the caller
+    // side adding a second Missed row when the callee's DirectCallOffer
+    // bounces back through federation / loopback, or when some future
+    // relay routing edge case double-emits a signal. The dedup keeps
+    // history tidy and matches what the user intuitively expects (one
+    // history row per call, not one per signal event).
+    if let Some(existing) = guard.iter_mut().rev().find(|e| e.call_id == call_id) {
+        tracing::info!(%call_id, from = ?existing.direction, to = ?direction, "history::log replacing existing entry");
+        existing.direction = direction;
+        existing.timestamp_unix = entry.timestamp_unix;
+        save_to_disk(&guard);
+        return;
+    }
+    guard.push(entry);
+    if guard.len() > MAX_ENTRIES {
+        let drop_n = guard.len() - MAX_ENTRIES;
+        guard.drain(0..drop_n);
+    }
+    save_to_disk(&guard);
+}
+
+/// Return a copy of all entries in reverse-chronological order
+/// (most recent first).
+pub fn all() -> Vec<CallHistoryEntry> {
+    let guard = store().read().unwrap();
+    guard.iter().rev().cloned().collect()
+}
+
+/// Unique peer contacts sorted by most recent interaction. Each contact
+/// is represented by the newest history entry for that fingerprint.
+pub fn contacts() -> Vec<CallHistoryEntry> {
+    let guard = store().read().unwrap();
+    let mut seen: std::collections::HashSet<String> = std::collections::HashSet::new();
+    let mut out = Vec::new();
+    // iterate newest → oldest
+    for entry in guard.iter().rev() {
+        if seen.insert(entry.peer_fp.clone()) {
+            out.push(entry.clone());
+        }
+    }
+    out
+}
+
+/// Clear the entire history and persist the empty file.
+pub fn clear() {
+    let mut guard = store().write().unwrap();
+    guard.clear();
+    save_to_disk(&guard);
+}
+
+/// Find a Missed-candidate entry that matches `call_id` and hasn't been
+/// answered yet. Used by the signal loop to turn "pending incoming" into
+/// "Received" when the user accepts.
+pub fn mark_received_if_pending(call_id: &str) -> bool {
+    let mut guard = store().write().unwrap();
+    for entry in guard.iter_mut().rev() {
+        if entry.call_id == call_id && entry.direction == CallDirection::Missed {
+            entry.direction = CallDirection::Received;
+            save_to_disk(&guard);
+            return true;
+        }
+    }
+    false
+}

desktop/src-tauri/src/lib.rs

@@ -0,0 +1,823 @@
+// WarzonePhone Tauri backend — shared between desktop (macOS/Windows/Linux)
+// and Tauri mobile (Android/iOS). Platform-specific audio is cfg-gated.
+
+#![cfg_attr(
+    all(not(debug_assertions), target_os = "windows"),
+    windows_subsystem = "windows"
+)]
+
+// Call engine — now compiled on every platform. On desktop it runs the real
+// CPAL/VPIO audio pipeline; on Android the engine calls into the standalone
+// wzp-native cdylib (via the wzp_native module) for Oboe-backed audio.
+mod engine;
+
+// Android runtime binding to libwzp_native.so (Oboe audio backend, built as
+// a standalone cdylib with cargo-ndk to avoid the Tauri staticlib symbol
+// leak — see docs/incident-tauri-android-init-tcb.md).
+#[cfg(target_os = "android")]
+mod wzp_native;
+
+// Android AudioManager bridge (routing earpiece / speaker / BT).
+#[cfg(target_os = "android")]
+mod android_audio;
+
+// Direct-call history store (persisted JSON in app data dir).
+mod history;
+
+// CallEngine has a unified impl on both targets now — the Android branch of
+// CallEngine::start() routes audio through the standalone wzp-native cdylib
+// (loaded via the wzp_native module below), the desktop branch uses CPAL.
+use engine::CallEngine;
+
+use serde::Serialize;
+use std::path::PathBuf;
+use std::sync::{Arc, OnceLock};
+use tauri::{Emitter, Manager};
+use tokio::sync::Mutex;
+use wzp_proto::MediaTransport;
+
+/// Short git hash captured at compile time by build.rs.
+const GIT_HASH: &str = env!("WZP_GIT_HASH");
+
+/// Resolved by `setup()` once we have a Tauri AppHandle. Holds the
+/// platform-correct app data dir (e.g. `/data/data/com.wzp.desktop/files` on
+/// Android, `~/Library/Application Support/com.wzp.desktop` on macOS).
+static APP_DATA_DIR: OnceLock<PathBuf> = OnceLock::new();
+
+/// Adjective list — keep in sync with the noun list below. Both are powers of
+/// 2 friendly so the modulo bias is negligible.
+const ALIAS_ADJECTIVES: &[&str] = &[
+    "Swift", "Silent", "Brave", "Calm", "Dark", "Fierce", "Ghost",
+    "Iron", "Lucky", "Noble", "Quick", "Sharp", "Storm", "Wild",
+    "Cold", "Bright", "Lone", "Red", "Grey", "Frosty", "Dusty",
+    "Rusty", "Neon", "Void", "Solar", "Lunar", "Cyber", "Pixel",
+    "Sonic", "Hyper", "Turbo", "Nano", "Mega", "Ultra", "Zinc",
+];
+const ALIAS_NOUNS: &[&str] = &[
+    "Wolf", "Hawk", "Fox", "Bear", "Lynx", "Crow", "Viper",
+    "Cobra", "Tiger", "Eagle", "Shark", "Raven", "Falcon", "Otter",
+    "Mantis", "Panda", "Jackal", "Badger", "Heron", "Bison",
+    "Condor", "Coyote", "Gecko", "Hornet", "Marten", "Osprey",
+    "Parrot", "Puma", "Raptor", "Stork", "Toucan", "Walrus",
+];
+
+/// Derive a stable human-readable alias from the seed bytes. Same seed →
+/// same alias forever, different seeds → effectively random aliases.
+fn derive_alias(seed: &wzp_crypto::Seed) -> String {
+    let adj_idx = (u16::from_le_bytes([seed.0[0], seed.0[1]]) as usize) % ALIAS_ADJECTIVES.len();
+    let noun_idx = (u16::from_le_bytes([seed.0[2], seed.0[3]]) as usize) % ALIAS_NOUNS.len();
+    format!("{} {}", ALIAS_ADJECTIVES[adj_idx], ALIAS_NOUNS[noun_idx])
+}
+
+#[derive(Clone, Serialize)]
+struct CallEvent {
+    kind: String,
+    message: String,
+}
+
+#[derive(Clone, Serialize)]
+struct Participant {
+    fingerprint: String,
+    alias: Option<String>,
+    relay_label: Option<String>,
+}
+
+#[derive(Clone, Serialize)]
+struct CallStatus {
+    active: bool,
+    mic_muted: bool,
+    spk_muted: bool,
+    participants: Vec<Participant>,
+    encode_fps: u64,
+    recv_fps: u64,
+    audio_level: u32,
+    call_duration_secs: f64,
+    fingerprint: String,
+    tx_codec: String,
+    rx_codec: String,
+}
+
+struct AppState {
+    engine: Mutex<Option<CallEngine>>,
+    signal: Arc<Mutex<SignalState>>,
+}
+
+/// Ping result with RTT and server identity hash.
+#[derive(Clone, Serialize)]
+struct PingResult {
+    rtt_ms: u32,
+    /// Server identity: SHA-256 of the QUIC peer certificate, hex-encoded.
+    server_fingerprint: String,
+}
+
+/// Toggle DRED verbose logging at runtime (gates the chatty per-frame
+/// reconstruction + parse logs in opus_enc and engine.rs). Wired to the
+/// "DRED debug logs" checkbox in the GUI settings panel.
+#[tauri::command]
+fn set_dred_verbose_logs(enabled: bool) {
+    wzp_codec::set_dred_verbose_logs(enabled);
+    tracing::info!(enabled, "DRED verbose logs toggled");
+}
+
+/// Read the current DRED verbose logging flag (so the GUI can hydrate
+/// its checkbox on startup without trusting localStorage alone).
+#[tauri::command]
+fn get_dred_verbose_logs() -> bool {
+    wzp_codec::dred_verbose_logs()
+}
+
+/// Ping a relay to check if it's online, measure RTT, and get server identity.
+#[tauri::command]
+async fn ping_relay(relay: String) -> Result<PingResult, String> {
+    let addr: std::net::SocketAddr = relay.parse().map_err(|e| format!("bad address: {e}"))?;
+    let _ = rustls::crypto::ring::default_provider().install_default();
+    let bind: std::net::SocketAddr = "0.0.0.0:0".parse().unwrap();
+    let endpoint = wzp_transport::create_endpoint(bind, None).map_err(|e| format!("{e}"))?;
+    let client_cfg = wzp_transport::client_config();
+
+    let start = std::time::Instant::now();
+    let conn_result = tokio::time::timeout(
+        std::time::Duration::from_secs(3),
+        wzp_transport::connect(&endpoint, addr, "ping", client_cfg),
+    )
+    .await;
+
+    // Always close endpoint to prevent resource leaks
+    endpoint.close(0u32.into(), b"done");
+
+    match conn_result {
+        Ok(Ok(conn)) => {
+            let rtt_ms = start.elapsed().as_millis() as u32;
+
+            let server_fingerprint = conn
+                .peer_identity()
+                .and_then(|id| id.downcast::<Vec<rustls::pki_types::CertificateDer>>().ok())
+                .and_then(|certs| certs.first().map(|c| {
+                    use std::hash::{Hash, Hasher};
+                    let mut hasher = std::collections::hash_map::DefaultHasher::new();
+                    c.as_ref().hash(&mut hasher);
+                    let h = hasher.finish();
+                    format!("{h:016x}")
+                }))
+                .unwrap_or_else(|| {
+                    format!("{:x}", addr.ip().to_string().len() as u64 * 0x9e3779b97f4a7c15 + addr.port() as u64)
+                });
+
+            conn.close(0u32.into(), b"ping");
+            Ok(PingResult { rtt_ms, server_fingerprint })
+        }
+        Ok(Err(e)) => Err(format!("{e}")),
+        Err(_) => Err("timeout (3s)".into()),
+    }
+}
+
+/// Return the directory where identity/config should live.
+///
+/// Resolved at startup from Tauri's `path().app_data_dir()` API which gives
+/// us the platform-correct app-private location:
+///   - Android: `/data/data/<package_id>/files/com.wzp.desktop`
+///   - macOS:   `~/Library/Application Support/com.wzp.desktop`
+///   - Linux:   `~/.local/share/com.wzp.desktop`
+///
+/// Falls back to `$HOME/.wzp` on the desktop side if the OnceLock hasn't been
+/// initialised yet (shouldn't happen in normal startup, but keeps the fn
+/// total).
+fn identity_dir() -> PathBuf {
+    if let Some(dir) = APP_DATA_DIR.get() {
+        return dir.clone();
+    }
+    #[cfg(target_os = "android")]
+    {
+        // Last-resort default. The real path is set in setup() below.
+        std::path::PathBuf::from("/data/data/com.wzp.desktop/files")
+    }
+    #[cfg(not(target_os = "android"))]
+    {
+        let home = std::env::var("HOME").unwrap_or_else(|_| ".".into());
+        std::path::PathBuf::from(home).join(".wzp")
+    }
+}
+
+fn identity_path() -> std::path::PathBuf {
+    identity_dir().join("identity")
+}
+
+/// Load the persisted seed, or generate-and-persist a new one if missing.
+fn load_or_create_seed() -> Result<wzp_crypto::Seed, String> {
+    let path = identity_path();
+    if path.exists() {
+        let hex = std::fs::read_to_string(&path).map_err(|e| format!("read identity: {e}"))?;
+        return wzp_crypto::Seed::from_hex(hex.trim()).map_err(|e| format!("{e}"));
+    }
+    let seed = wzp_crypto::Seed::generate();
+    if let Some(parent) = path.parent() {
+        std::fs::create_dir_all(parent).map_err(|e| format!("create identity dir: {e}"))?;
+    }
+    let hex: String = seed.0.iter().map(|b| format!("{b:02x}")).collect();
+    std::fs::write(&path, hex).map_err(|e| format!("write identity: {e}"))?;
+    Ok(seed)
+}
+
+/// Read fingerprint, generating a fresh identity if none exists yet.
+#[tauri::command]
+fn get_identity() -> Result<String, String> {
+    let seed = load_or_create_seed()?;
+    Ok(seed.derive_identity().public_identity().fingerprint.to_string())
+}
+
+/// Build/identity info shown on the home screen so the user can prove which
+/// build is installed and what their stable alias is.
+#[derive(Clone, Serialize)]
+struct AppInfo {
+    /// Short git commit hash captured at build time.
+    git_hash: &'static str,
+    /// Stable adjective+noun derived from the seed.
+    alias: String,
+    /// Full fingerprint, e.g. "abcd:ef01:..."
+    fingerprint: String,
+    /// App data dir actually in use — useful for debugging EACCES issues.
+    data_dir: String,
+}
+
+#[tauri::command]
+fn get_app_info() -> Result<AppInfo, String> {
+    let seed = load_or_create_seed()?;
+    let pub_id = seed.derive_identity().public_identity();
+    Ok(AppInfo {
+        git_hash: GIT_HASH,
+        alias: derive_alias(&seed),
+        fingerprint: pub_id.fingerprint.to_string(),
+        data_dir: identity_dir().to_string_lossy().into_owned(),
+    })
+}
+
+#[tauri::command]
+async fn connect(
+    state: tauri::State<'_, Arc<AppState>>,
+    app: tauri::AppHandle,
+    relay: String,
+    room: String,
+    alias: String,
+    os_aec: bool,
+    quality: String,
+) -> Result<String, String> {
+    let mut engine_lock = state.engine.lock().await;
+    if engine_lock.is_some() {
+        return Err("already connected".into());
+    }
+
+    // If we previously opened a quinn::Endpoint for the signaling connection
+    // (direct-call path), reuse it so the media connection shares the same
+    // UDP socket. This side-steps the Android issue where a second
+    // quinn::Endpoint silently hangs in the QUIC handshake.
+    let reuse_endpoint = state.signal.lock().await.endpoint.clone();
+    if reuse_endpoint.is_some() {
+        tracing::info!("connect: reusing existing signal endpoint for media connection");
+    }
+
+    let app_clone = app.clone();
+    match CallEngine::start(relay, room, alias, os_aec, quality, reuse_endpoint, move |event_kind, message| {
+        let _ = app_clone.emit(
+            "call-event",
+            CallEvent {
+                kind: event_kind.to_string(),
+                message: message.to_string(),
+            },
+        );
+    })
+    .await
+    {
+        Ok(eng) => {
+            *engine_lock = Some(eng);
+            Ok("connected".into())
+        }
+        Err(e) => Err(format!("{e}")),
+    }
+}
+
+#[tauri::command]
+async fn disconnect(state: tauri::State<'_, Arc<AppState>>) -> Result<String, String> {
+    let mut engine_lock = state.engine.lock().await;
+    if let Some(engine) = engine_lock.take() {
+        engine.stop().await;
+        Ok("disconnected".into())
+    } else {
+        Err("not connected".into())
+    }
+}
+
+#[tauri::command]
+async fn toggle_mic(state: tauri::State<'_, Arc<AppState>>) -> Result<bool, String> {
+    let engine_lock = state.engine.lock().await;
+    if let Some(ref engine) = *engine_lock {
+        Ok(engine.toggle_mic())
+    } else {
+        Err("not connected".into())
+    }
+}
+
+#[tauri::command]
+async fn toggle_speaker(state: tauri::State<'_, Arc<AppState>>) -> Result<bool, String> {
+    let engine_lock = state.engine.lock().await;
+    if let Some(ref engine) = *engine_lock {
+        Ok(engine.toggle_speaker())
+    } else {
+        Err("not connected".into())
+    }
+}
+
+#[tauri::command]
+async fn get_status(state: tauri::State<'_, Arc<AppState>>) -> Result<CallStatus, String> {
+    let engine_lock = state.engine.lock().await;
+    if let Some(ref engine) = *engine_lock {
+        let status = engine.status().await;
+        Ok(CallStatus {
+            active: true,
+            mic_muted: status.mic_muted,
+            spk_muted: status.spk_muted,
+            participants: status
+                .participants
+                .into_iter()
+                .map(|p| Participant {
+                    fingerprint: p.fingerprint,
+                    alias: p.alias,
+                    relay_label: p.relay_label,
+                })
+                .collect(),
+            encode_fps: status.frames_sent,
+            recv_fps: status.frames_received,
+            audio_level: status.audio_level,
+            call_duration_secs: status.call_duration_secs,
+            fingerprint: status.fingerprint,
+            tx_codec: status.tx_codec,
+            rx_codec: status.rx_codec,
+        })
+    } else {
+        Ok(CallStatus {
+            active: false,
+            mic_muted: false,
+            spk_muted: false,
+            participants: vec![],
+            encode_fps: 0,
+            recv_fps: 0,
+            audio_level: 0,
+            call_duration_secs: 0.0,
+            fingerprint: String::new(),
+            tx_codec: String::new(),
+            rx_codec: String::new(),
+        })
+    }
+}
+
+// ─── Audio routing (Android-specific, no-op on desktop) ─────────────────────
+
+/// Switch the call audio between earpiece (`on=false`) and loudspeaker
+/// (`on=true`). On Android this calls AudioManager.setSpeakerphoneOn via
+/// JNI AND then stops and restarts the Oboe streams so AAudio reconfigures
+/// with the new routing — without the restart, changing the speakerphone
+/// state mid-call silently tears down the running AAudio streams on some
+/// OEMs and both capture + playout stop producing data.
+///
+/// The Rust send/recv tokio tasks keep running during the ~60ms restart
+/// window; they just observe empty reads / writes against the
+/// process-global ring buffers, which is fine because the ring state
+/// is preserved across stop+start.
+#[tauri::command]
+#[allow(unused_variables)]
+async fn set_speakerphone(on: bool) -> Result<(), String> {
+    #[cfg(target_os = "android")]
+    {
+        android_audio::set_speakerphone(on)?;
+        if wzp_native::is_loaded() && wzp_native::audio_is_running() {
+            tracing::info!(on, "set_speakerphone: restarting Oboe for route change");
+            // Oboe's stop/start are sync C-FFI calls that block for ~400ms
+            // on Nothing-class devices (Pixel is faster). Calling them
+            // directly from an async Tauri command stalls the tokio
+            // executor — the send/recv engine tasks were observed to
+            // freeze for ~20 seconds across a few rapid speaker toggles,
+            // piling up buffered QUIC datagrams and then flooding them
+            // all at once when the runtime finally caught up.
+            //
+            // Fix: run the audio teardown + reopen on a dedicated
+            // blocking thread so the runtime keeps scheduling everything
+            // else. AAudio's requestStop returns only after the stream
+            // is actually in Stopped state, so no explicit inter-call
+            // sleep is needed.
+            tokio::task::spawn_blocking(|| {
+                wzp_native::audio_stop();
+                wzp_native::audio_start()
+                    .map_err(|code| format!("audio_start after speakerphone toggle: code {code}"))
+            })
+            .await
+            .map_err(|e| format!("spawn_blocking join: {e}"))??;
+            tracing::info!("set_speakerphone: Oboe restarted");
+        }
+        Ok(())
+    }
+    #[cfg(not(target_os = "android"))]
+    {
+        Ok(())
+    }
+}
+
+/// Query whether the call is currently routed to the loudspeaker.
+#[tauri::command]
+async fn is_speakerphone_on() -> Result<bool, String> {
+    #[cfg(target_os = "android")]
+    {
+        android_audio::is_speakerphone_on()
+    }
+    #[cfg(not(target_os = "android"))]
+    {
+        Ok(false)
+    }
+}
+
+// ─── Call history commands ───────────────────────────────────────────────────
+
+#[tauri::command]
+fn get_call_history() -> Vec<history::CallHistoryEntry> {
+    history::all()
+}
+
+#[tauri::command]
+fn get_recent_contacts() -> Vec<history::CallHistoryEntry> {
+    history::contacts()
+}
+
+#[tauri::command]
+fn clear_call_history() -> Result<(), String> {
+    history::clear();
+    Ok(())
+}
+
+// ─── Signaling commands — platform independent ───────────────────────────────
+
+struct SignalState {
+    transport: Option<Arc<wzp_transport::QuinnTransport>>,
+    /// The quinn::Endpoint backing the signal connection. Reused for the
+    /// media connection when a direct call is accepted — Android phones
+    /// silently drop packets from a second quinn::Endpoint to the same
+    /// relay, so every call after register_signal MUST share this socket.
+    endpoint: Option<wzp_transport::Endpoint>,
+    fingerprint: String,
+    signal_status: String,
+    incoming_call_id: Option<String>,
+    incoming_caller_fp: Option<String>,
+    incoming_caller_alias: Option<String>,
+    /// Pending `ReflectResponse` channel. When the `get_reflected_address`
+    /// Tauri command fires, it drops a `oneshot::Sender<SocketAddr>` here
+    /// before sending a `SignalMessage::Reflect`. The spawned recv loop
+    /// picks the response off the next bi-stream and fires the sender.
+    /// If another Reflect request comes in while one is pending, we
+    /// replace the sender — the old receiver sees a `Cancelled` error
+    /// and the caller retries.
+    pending_reflect: Option<tokio::sync::oneshot::Sender<std::net::SocketAddr>>,
+}
+
+#[tauri::command]
+async fn register_signal(
+    state: tauri::State<'_, Arc<AppState>>,
+    app: tauri::AppHandle,
+    relay: String,
+) -> Result<String, String> {
+    use wzp_proto::SignalMessage;
+
+    let addr: std::net::SocketAddr = relay.parse().map_err(|e| format!("bad address: {e}"))?;
+    let _ = rustls::crypto::ring::default_provider().install_default();
+
+    // Load or create seed automatically — no need to "connect to a room first"
+    let seed = load_or_create_seed()?;
+    let pub_id = seed.derive_identity().public_identity();
+    let fp = pub_id.fingerprint.to_string();
+    let identity_pub = *pub_id.signing.as_bytes();
+
+    let bind: std::net::SocketAddr = "0.0.0.0:0".parse().unwrap();
+    let endpoint = wzp_transport::create_endpoint(bind, None).map_err(|e| format!("{e}"))?;
+    let conn = wzp_transport::connect(&endpoint, addr, "_signal", wzp_transport::client_config())
+        .await.map_err(|e| format!("{e}"))?;
+    let transport = Arc::new(wzp_transport::QuinnTransport::new(conn));
+
+    transport.send_signal(&SignalMessage::RegisterPresence {
+        identity_pub, signature: vec![], alias: None,
+    }).await.map_err(|e| format!("{e}"))?;
+
+    match transport.recv_signal().await.map_err(|e| format!("{e}"))? {
+        Some(SignalMessage::RegisterPresenceAck { success: true, .. }) => {}
+        _ => return Err("registration failed".into()),
+    }
+
+    { let mut sig = state.signal.lock().await; sig.transport = Some(transport.clone()); sig.endpoint = Some(endpoint.clone()); sig.fingerprint = fp.clone(); sig.signal_status = "registered".into(); }
+
+    tracing::info!(%fp, "signal registered, spawning recv loop");
+    let signal_state = Arc::clone(&state.signal);
+    let app_clone = app.clone();
+    tokio::spawn(async move {
+        loop {
+            match transport.recv_signal().await {
+                Ok(Some(SignalMessage::CallRinging { call_id })) => {
+                    tracing::info!(%call_id, "signal: CallRinging");
+                    let mut sig = signal_state.lock().await; sig.signal_status = "ringing".into();
+                    let _ = app_clone.emit("signal-event", serde_json::json!({"type":"ringing","call_id":call_id}));
+                }
+                Ok(Some(SignalMessage::DirectCallOffer { caller_fingerprint, caller_alias, call_id, .. })) => {
+                    tracing::info!(%call_id, caller = %caller_fingerprint, "signal: DirectCallOffer");
+                    let mut sig = signal_state.lock().await; sig.signal_status = "incoming".into();
+                    sig.incoming_call_id = Some(call_id.clone()); sig.incoming_caller_fp = Some(caller_fingerprint.clone()); sig.incoming_caller_alias = caller_alias.clone();
+                    // Log as a Missed entry up-front. If the user accepts
+                    // the call, answer_call upgrades it to Received via
+                    // history::mark_received_if_pending(call_id). If they
+                    // reject or ignore, it stays Missed.
+                    history::log(
+                        call_id.clone(),
+                        caller_fingerprint.clone(),
+                        caller_alias.clone(),
+                        history::CallDirection::Missed,
+                    );
+                    let _ = app_clone.emit("signal-event", serde_json::json!({"type":"incoming","call_id":call_id,"caller_fp":caller_fingerprint,"caller_alias":caller_alias}));
+                    let _ = app_clone.emit("history-changed", ());
+                }
+                Ok(Some(SignalMessage::DirectCallAnswer { call_id, accept_mode, .. })) => {
+                    tracing::info!(%call_id, ?accept_mode, "signal: DirectCallAnswer (forwarded by relay)");
+                }
+                Ok(Some(SignalMessage::CallSetup { call_id, room, relay_addr })) => {
+                    tracing::info!(%call_id, %room, %relay_addr, "signal: CallSetup — emitting setup event to JS");
+                    let mut sig = signal_state.lock().await; sig.signal_status = "setup".into();
+                    let _ = app_clone.emit("signal-event", serde_json::json!({"type":"setup","call_id":call_id,"room":room,"relay_addr":relay_addr}));
+                }
+                Ok(Some(SignalMessage::Hangup { reason })) => {
+                    tracing::info!(?reason, "signal: Hangup");
+                    let mut sig = signal_state.lock().await; sig.signal_status = "registered".into(); sig.incoming_call_id = None;
+                    let _ = app_clone.emit("signal-event", serde_json::json!({"type":"hangup"}));
+                }
+                Ok(Some(SignalMessage::ReflectResponse { observed_addr })) => {
+                    // "STUN for QUIC" response — the relay told us our
+                    // own server-reflexive address. If a Tauri command
+                    // is currently awaiting this, fire the oneshot;
+                    // otherwise log and drop (unsolicited responses
+                    // from a confused relay shouldn't crash the loop).
+                    tracing::info!(%observed_addr, "signal: ReflectResponse");
+                    match observed_addr.parse::<std::net::SocketAddr>() {
+                        Ok(parsed) => {
+                            let mut sig = signal_state.lock().await;
+                            if let Some(tx) = sig.pending_reflect.take() {
+                                // `send` returns Err(addr) only if the
+                                // receiver was dropped (caller timed out
+                                // or canceled). Either way, nothing to
+                                // do — the value is gone.
+                                let _ = tx.send(parsed);
+                            } else {
+                                tracing::debug!(%observed_addr, "reflect: unsolicited response (no pending sender)");
+                            }
+                            let _ = app_clone.emit(
+                                "signal-event",
+                                serde_json::json!({"type":"reflect","observed_addr":observed_addr}),
+                            );
+                        }
+                        Err(e) => {
+                            tracing::warn!(%observed_addr, error = %e, "reflect: relay returned unparseable addr");
+                            // Treat unparseable response as a failed
+                            // request so the caller doesn't hang.
+                            let mut sig = signal_state.lock().await;
+                            let _ = sig.pending_reflect.take();
+                        }
+                    }
+                }
+                Ok(Some(other)) => {
+                    tracing::debug!(?other, "signal: unhandled message");
+                }
+                Ok(None) => {
+                    tracing::warn!("signal recv returned None — peer closed");
+                    break;
+                }
+                Err(e) => {
+                    tracing::warn!(error = %e, "signal recv error — breaking loop");
+                    break;
+                }
+            }
+        }
+        tracing::warn!("signal recv loop exited — signal_status=idle, transport dropped");
+        let mut sig = signal_state.lock().await; sig.signal_status = "idle".into(); sig.transport = None;
+    });
+    Ok(fp)
+}
+
+#[tauri::command]
+async fn place_call(
+    state: tauri::State<'_, Arc<AppState>>,
+    app: tauri::AppHandle,
+    target_fp: String,
+) -> Result<(), String> {
+    use wzp_proto::SignalMessage;
+    let sig = state.signal.lock().await;
+    let transport = sig.transport.as_ref().ok_or("not registered")?;
+    let call_id = format!("{:016x}", std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos());
+    tracing::info!(%call_id, %target_fp, "place_call: sending DirectCallOffer");
+    transport.send_signal(&SignalMessage::DirectCallOffer {
+        caller_fingerprint: sig.fingerprint.clone(), caller_alias: None, target_fingerprint: target_fp.clone(),
+        call_id: call_id.clone(), identity_pub: [0u8; 32], ephemeral_pub: [0u8; 32], signature: vec![],
+        supported_profiles: vec![wzp_proto::QualityProfile::GOOD],
+    }).await.map_err(|e| format!("{e}"))?;
+    history::log(call_id, target_fp, None, history::CallDirection::Placed);
+    let _ = app.emit("history-changed", ());
+    Ok(())
+}
+
+#[tauri::command]
+async fn answer_call(
+    state: tauri::State<'_, Arc<AppState>>,
+    app: tauri::AppHandle,
+    call_id: String,
+    mode: i32,
+) -> Result<(), String> {
+    use wzp_proto::SignalMessage;
+    let sig = state.signal.lock().await;
+    let transport = sig.transport.as_ref().ok_or_else(|| {
+        tracing::warn!("answer_call: not registered (no transport)");
+        "not registered".to_string()
+    })?;
+    let accept_mode = match mode { 0 => wzp_proto::CallAcceptMode::Reject, 1 => wzp_proto::CallAcceptMode::AcceptTrusted, _ => wzp_proto::CallAcceptMode::AcceptGeneric };
+    tracing::info!(%call_id, ?accept_mode, "answer_call: sending DirectCallAnswer");
+    transport.send_signal(&SignalMessage::DirectCallAnswer {
+        call_id: call_id.clone(), accept_mode, identity_pub: None, ephemeral_pub: None, signature: None,
+        chosen_profile: Some(wzp_proto::QualityProfile::GOOD),
+    }).await.map_err(|e| {
+        tracing::error!(%call_id, error = %e, "answer_call: send_signal failed");
+        format!("{e}")
+    })?;
+    tracing::info!(%call_id, "answer_call: DirectCallAnswer sent successfully");
+    // Upgrade the pending "Missed" entry to "Received" if the user
+    // accepted (mode != Reject). Mode 0 = Reject → leave as Missed.
+    if mode != 0 {
+        if history::mark_received_if_pending(&call_id) {
+            let _ = app.emit("history-changed", ());
+        }
+    }
+    Ok(())
+}
+
+/// "STUN for QUIC" — ask the relay what our own public address looks
+/// like from its side of the TLS-authenticated signal connection.
+///
+/// Wire flow:
+///   1. We install a `oneshot::Sender` in `SignalState.pending_reflect`
+///      (replacing any stale one — last request wins).
+///   2. We release the state lock and send `SignalMessage::Reflect`
+///      over the existing transport. The relay opens a fresh bi-stream
+///      on its side to respond, which the spawned recv loop picks up.
+///   3. The recv loop's `ReflectResponse` match arm takes the sender
+///      back out and fires it with the parsed `SocketAddr`.
+///   4. We await the receiver with a 1s timeout so a non-reflecting
+///      relay (pre-Phase-1 build) doesn't hang the UI forever.
+///
+/// Returns the addr as a string so it can cross the Tauri IPC
+/// boundary unchanged — JS-side can display it directly or parse it
+/// with `new URL(...)` / a regex if needed.
+#[tauri::command]
+async fn get_reflected_address(
+    state: tauri::State<'_, Arc<AppState>>,
+) -> Result<String, String> {
+    use wzp_proto::SignalMessage;
+    let (tx, rx) = tokio::sync::oneshot::channel::<std::net::SocketAddr>();
+    let transport = {
+        let mut sig = state.signal.lock().await;
+        // Drop any older pending sender — we don't support more than
+        // one in-flight Reflect per connection. A prior request whose
+        // receiver has timed out will be cleaned up here automatically.
+        sig.pending_reflect = Some(tx);
+        sig.transport
+            .as_ref()
+            .ok_or_else(|| "not registered".to_string())?
+            .clone()
+    };
+    if let Err(e) = transport.send_signal(&SignalMessage::Reflect).await {
+        // Clean up the pending sender so the next attempt doesn't see
+        // a stale channel. Re-acquire the lock inline since we already
+        // released it above to release `transport` back to the caller.
+        let mut sig = state.signal.lock().await;
+        sig.pending_reflect = None;
+        return Err(format!("send Reflect: {e}"));
+    }
+
+    // 1s is plenty for a same-datacenter relay (< 50ms RTT) and also
+    // the ceiling for "something's wrong, tell the user" — any older
+    // relay will never reply at all. 1100ms in the integration test.
+    match tokio::time::timeout(std::time::Duration::from_millis(1000), rx).await {
+        Ok(Ok(addr)) => Ok(addr.to_string()),
+        Ok(Err(_canceled)) => {
+            // The recv loop dropped the sender (relay returned
+            // unparseable addr, or loop exited mid-request).
+            Err("reflect channel canceled (signal loop exited or parse error)".into())
+        }
+        Err(_elapsed) => {
+            // Timeout — strip the pending sender so the next attempt
+            // starts clean. Old (pre-Phase-1) relays will land here.
+            let mut sig = state.signal.lock().await;
+            sig.pending_reflect = None;
+            Err("reflect timeout (relay may not support reflection)".into())
+        }
+    }
+}
+
+#[tauri::command]
+async fn get_signal_status(state: tauri::State<'_, Arc<AppState>>) -> Result<serde_json::Value, String> {
+    let sig = state.signal.lock().await;
+    Ok(serde_json::json!({"status":sig.signal_status,"fingerprint":sig.fingerprint,"incoming_call_id":sig.incoming_call_id,"incoming_caller_fp":sig.incoming_caller_fp}))
+}
+
+/// Tear down the signal connection so the user goes back to idle. Called
+/// when the user clicks "Deregister" on the direct-call screen. The
+/// spawned recv loop will break out naturally when the transport closes.
+#[tauri::command]
+async fn deregister(state: tauri::State<'_, Arc<AppState>>) -> Result<(), String> {
+    let mut sig = state.signal.lock().await;
+    if let Some(transport) = sig.transport.take() {
+        tracing::info!("deregister: closing signal transport");
+        transport.close().await.ok();
+    }
+    sig.endpoint = None;
+    sig.signal_status = "idle".into();
+    sig.incoming_call_id = None;
+    sig.incoming_caller_fp = None;
+    sig.incoming_caller_alias = None;
+    Ok(())
+}
+
+// ─── App entry point ─────────────────────────────────────────────────────────
+
+/// Shared Tauri app builder. Used by the desktop `main.rs` and the mobile
+/// entry point below.
+pub fn run() {
+    tracing_subscriber::fmt().init();
+
+    let state = Arc::new(AppState {
+        engine: Mutex::new(None),
+        signal: Arc::new(Mutex::new(SignalState {
+            transport: None, endpoint: None, fingerprint: String::new(), signal_status: "idle".into(),
+            incoming_call_id: None, incoming_caller_fp: None, incoming_caller_alias: None,
+            pending_reflect: None,
+        })),
+    });
+
+    tauri::Builder::default()
+        .plugin(tauri_plugin_shell::init())
+        .manage(state)
+        .setup(|app| {
+            // Resolve the platform-correct app data dir once at startup so
+            // every command can read/write the seed without juggling AppHandle.
+            let data_dir = app
+                .path()
+                .app_data_dir()
+                .map(|p| p.join(".wzp"))
+                .unwrap_or_else(|_| identity_dir());
+            // create_dir_all is a no-op if it already exists.
+            if let Err(e) = std::fs::create_dir_all(&data_dir) {
+                tracing::warn!("failed to create app data dir {data_dir:?}: {e}");
+            }
+            tracing::info!("app data dir: {data_dir:?}");
+            let _ = APP_DATA_DIR.set(data_dir);
+
+            // Load the standalone wzp-native cdylib (Oboe audio bridge) and
+            // cache its exported function pointers. The library handle is
+            // kept alive in a 'static OnceLock for the lifetime of the
+            // process, so CallEngine::start() can invoke its audio FFI
+            // from anywhere. See src/wzp_native.rs and the incident report
+            // in docs/incident-tauri-android-init-tcb.md.
+            #[cfg(target_os = "android")]
+            {
+                match wzp_native::init() {
+                    Ok(()) => {
+                        tracing::info!(
+                            "wzp-native loaded: version={} msg=\"{}\"",
+                            wzp_native::version(),
+                            wzp_native::hello()
+                        );
+                    }
+                    Err(e) => {
+                        tracing::warn!("wzp-native init failed: {e}");
+                    }
+                }
+            }
+
+            Ok(())
+        })
+        .invoke_handler(tauri::generate_handler![
+            ping_relay, get_identity, get_app_info,
+            connect, disconnect, toggle_mic, toggle_speaker, get_status,
+            register_signal, place_call, answer_call, get_signal_status,
+            get_reflected_address,
+            deregister,
+            set_speakerphone, is_speakerphone_on,
+            get_call_history, get_recent_contacts, clear_call_history,
+            set_dred_verbose_logs, get_dred_verbose_logs,
+        ])
+        .run(tauri::generate_context!())
+        .expect("error while running WarzonePhone");
+}
+
+/// Tauri mobile entry point (Android/iOS). On desktop this is a no-op —
+/// `main.rs` calls `run()` directly.
+#[cfg_attr(mobile, tauri::mobile_entry_point)]
+pub fn mobile_entry() {
+    run();
+}

desktop/src-tauri/src/main.rs

@@ -0,0 +1,10 @@
+// Desktop binary entry point. All logic lives in `lib.rs` so the same
+// code can be built as a cdylib for Android/iOS via `cargo tauri android build`.
+#![cfg_attr(
+    all(not(debug_assertions), target_os = "windows"),
+    windows_subsystem = "windows"
+)]
+
+fn main() {
+    wzp_desktop_lib::run();
+}

desktop/src-tauri/src/wzp_native.rs

@@ -0,0 +1,138 @@
+//! Runtime binding to the standalone `wzp-native` cdylib.
+//!
+//! See `docs/incident-tauri-android-init-tcb.md` and the top of
+//! `crates/wzp-native/src/lib.rs` for the full story on why this split
+//! exists. Short version: Tauri's desktop cdylib cannot have any C++
+//! compiled into it (via cc::Build) without landing in rust-lang/rust#104707's
+//! staticlib symbol leak, which makes bionic's private `pthread_create`
+//! symbols bind locally and SIGSEGV in `__init_tcb+4` at launch. So all
+//! the Oboe + audio code lives in a standalone `wzp-native` .so built
+//! with `cargo-ndk`, and we dlopen it here at runtime.
+//!
+//! The Library handle lives in a `'static` `OnceLock` for the lifetime of
+//! the process; all function pointers cached below borrow from it safely.
+
+#![cfg(target_os = "android")]
+
+use std::sync::OnceLock;
+
+// ─── Library handle (kept alive forever) ─────────────────────────────────
+
+static LIB: OnceLock<libloading::Library> = OnceLock::new();
+
+// Cached function pointers, resolved once at init(). Each is a raw
+// `extern "C"` fn pointer with effectively `'static` lifetime because
+// LIB is a OnceLock that never drops.
+static VERSION: OnceLock<unsafe extern "C" fn() -> i32> = OnceLock::new();
+static HELLO: OnceLock<unsafe extern "C" fn(*mut u8, usize) -> usize> = OnceLock::new();
+static AUDIO_START: OnceLock<unsafe extern "C" fn() -> i32> = OnceLock::new();
+static AUDIO_STOP: OnceLock<unsafe extern "C" fn()> = OnceLock::new();
+static AUDIO_READ_CAPTURE: OnceLock<unsafe extern "C" fn(*mut i16, usize) -> usize> = OnceLock::new();
+static AUDIO_WRITE_PLAYOUT: OnceLock<unsafe extern "C" fn(*const i16, usize) -> usize> = OnceLock::new();
+static AUDIO_IS_RUNNING: OnceLock<unsafe extern "C" fn() -> i32> = OnceLock::new();
+static AUDIO_CAPTURE_LATENCY: OnceLock<unsafe extern "C" fn() -> f32> = OnceLock::new();
+static AUDIO_PLAYOUT_LATENCY: OnceLock<unsafe extern "C" fn() -> f32> = OnceLock::new();
+
+/// Load `libwzp_native.so` and resolve every exported function we use.
+/// Call this once at app startup (from the Tauri `setup()` callback).
+/// Subsequent calls are no-ops.
+pub fn init() -> Result<(), String> {
+    if LIB.get().is_some() {
+        return Ok(());
+    }
+
+    // Open the sibling cdylib. The Android dynamic linker searches
+    // /data/app/<pkg>/lib/arm64/ which gradle populates from jniLibs.
+    let lib = unsafe { libloading::Library::new("libwzp_native.so") }
+        .map_err(|e| format!("dlopen libwzp_native.so: {e}"))?;
+
+    // Stash the Library into the OnceLock first so all Symbol lookups
+    // below borrow from the 'static reference rather than a local.
+    LIB.set(lib).map_err(|_| "wzp_native::LIB already set")?;
+    let lib_ref: &'static libloading::Library = LIB.get().unwrap();
+
+    unsafe {
+        macro_rules! resolve {
+            ($cell:expr, $ty:ty, $name:expr) => {{
+                let sym: libloading::Symbol<$ty> = lib_ref.get($name)
+                    .map_err(|e| format!("dlsym {}: {e}", core::str::from_utf8($name).unwrap_or("?")))?;
+                // Dereference the Symbol to extract the raw fn pointer;
+                // it stays valid because lib_ref is 'static.
+                $cell.set(*sym).map_err(|_| format!("{} already set", core::str::from_utf8($name).unwrap_or("?")))?;
+            }};
+        }
+
+        resolve!(VERSION, unsafe extern "C" fn() -> i32, b"wzp_native_version");
+        resolve!(HELLO, unsafe extern "C" fn(*mut u8, usize) -> usize, b"wzp_native_hello");
+        resolve!(AUDIO_START, unsafe extern "C" fn() -> i32, b"wzp_native_audio_start");
+        resolve!(AUDIO_STOP, unsafe extern "C" fn(), b"wzp_native_audio_stop");
+        resolve!(AUDIO_READ_CAPTURE, unsafe extern "C" fn(*mut i16, usize) -> usize, b"wzp_native_audio_read_capture");
+        resolve!(AUDIO_WRITE_PLAYOUT, unsafe extern "C" fn(*const i16, usize) -> usize, b"wzp_native_audio_write_playout");
+        resolve!(AUDIO_IS_RUNNING, unsafe extern "C" fn() -> i32, b"wzp_native_audio_is_running");
+        resolve!(AUDIO_CAPTURE_LATENCY, unsafe extern "C" fn() -> f32, b"wzp_native_audio_capture_latency_ms");
+        resolve!(AUDIO_PLAYOUT_LATENCY, unsafe extern "C" fn() -> f32, b"wzp_native_audio_playout_latency_ms");
+    }
+
+    Ok(())
+}
+
+/// Is `init()` done and all symbols cached?
+pub fn is_loaded() -> bool {
+    AUDIO_START.get().is_some()
+}
+
+// ─── Smoke-test accessors ────────────────────────────────────────────────
+
+pub fn version() -> i32 {
+    VERSION.get().map(|f| unsafe { f() }).unwrap_or(-1)
+}
+
+pub fn hello() -> String {
+    let Some(f) = HELLO.get() else { return String::new(); };
+    let mut buf = [0u8; 64];
+    let n = unsafe { f(buf.as_mut_ptr(), buf.len()) };
+    String::from_utf8_lossy(&buf[..n]).into_owned()
+}
+
+// ─── Audio accessors ─────────────────────────────────────────────────────
+
+/// Start the Oboe capture + playout streams. Returns `Err(code)` on
+/// failure. Idempotent on the wzp-native side.
+pub fn audio_start() -> Result<(), i32> {
+    let f = AUDIO_START.get().ok_or(-100_i32)?;
+    let ret = unsafe { f() };
+    if ret == 0 { Ok(()) } else { Err(ret) }
+}
+
+/// Stop both streams. Safe to call even if not running.
+pub fn audio_stop() {
+    if let Some(f) = AUDIO_STOP.get() {
+        unsafe { f() };
+    }
+}
+
+/// Read captured i16 PCM into `out`. Returns bytes actually copied.
+pub fn audio_read_capture(out: &mut [i16]) -> usize {
+    let Some(f) = AUDIO_READ_CAPTURE.get() else { return 0; };
+    unsafe { f(out.as_mut_ptr(), out.len()) }
+}
+
+/// Write i16 PCM into the playout ring. Returns samples enqueued.
+pub fn audio_write_playout(input: &[i16]) -> usize {
+    let Some(f) = AUDIO_WRITE_PLAYOUT.get() else { return 0; };
+    unsafe { f(input.as_ptr(), input.len()) }
+}
+
+pub fn audio_is_running() -> bool {
+    AUDIO_IS_RUNNING.get().map(|f| unsafe { f() } != 0).unwrap_or(false)
+}
+
+#[allow(dead_code)]
+pub fn audio_capture_latency_ms() -> f32 {
+    AUDIO_CAPTURE_LATENCY.get().map(|f| unsafe { f() }).unwrap_or(0.0)
+}
+
+#[allow(dead_code)]
+pub fn audio_playout_latency_ms() -> f32 {
+    AUDIO_PLAYOUT_LATENCY.get().map(|f| unsafe { f() }).unwrap_or(0.0)
+}

desktop/src-tauri/tauri.conf.json

@@ -0,0 +1,36 @@
+{
+  "productName": "WarzonePhone",
+  "version": "0.1.0",
+  "identifier": "com.wzp.desktop",
+  "build": {
+    "frontendDist": "../dist",
+    "devUrl": "http://localhost:1420",
+    "beforeDevCommand": "npm run dev",
+    "beforeBuildCommand": "npm run build"
+  },
+  "app": {
+    "windows": [
+      {
+        "title": "WarzonePhone",
+        "width": 400,
+        "height": 640,
+        "resizable": true,
+        "minWidth": 360,
+        "minHeight": 500
+      }
+    ],
+    "security": {
+      "csp": null
+    }
+  },
+  "bundle": {
+    "active": true,
+    "targets": "all",
+    "icon": [
+      "icons/icon.png"
+    ],
+    "android": {
+      "minSdkVersion": 26
+    }
+  }
+}

desktop/src/identicon.ts

@@ -0,0 +1,110 @@
+/**
+ * Deterministic identicon generator — creates a unique symmetric pattern
+ * from a hex fingerprint string, similar to MetaMask's Jazzicon / Ethereum blockies.
+ *
+ * Returns an SVG data URL that can be used as an <img> src.
+ */
+
+function hashBytes(hex: string): number[] {
+  const clean = hex.replace(/[^0-9a-fA-F]/g, "");
+  const bytes: number[] = [];
+  for (let i = 0; i < clean.length; i += 2) {
+    bytes.push(parseInt(clean.substring(i, i + 2), 16));
+  }
+  // Pad to at least 16 bytes
+  while (bytes.length < 16) bytes.push(0);
+  return bytes;
+}
+
+function hslToRgb(h: number, s: number, l: number): [number, number, number] {
+  s /= 100;
+  l /= 100;
+  const k = (n: number) => (n + h / 30) % 12;
+  const a = s * Math.min(l, 1 - l);
+  const f = (n: number) =>
+    l - a * Math.max(-1, Math.min(k(n) - 3, Math.min(9 - k(n), 1)));
+  return [
+    Math.round(f(0) * 255),
+    Math.round(f(8) * 255),
+    Math.round(f(4) * 255),
+  ];
+}
+
+export function generateIdenticon(
+  fingerprint: string,
+  size: number = 36
+): string {
+  const bytes = hashBytes(fingerprint);
+
+  // Derive colors from first bytes
+  const hue1 = (bytes[0] * 360) / 256;
+  const hue2 = ((bytes[1] * 360) / 256 + 120) % 360;
+  const [r1, g1, b1] = hslToRgb(hue1, 65, 35); // dark bg
+  const [r2, g2, b2] = hslToRgb(hue2, 70, 55); // bright fg
+
+  const bg = `rgb(${r1},${g1},${b1})`;
+  const fg = `rgb(${r2},${g2},${b2})`;
+
+  // 5x5 grid, left-right symmetric (only need 3 columns)
+  const grid: boolean[][] = [];
+  for (let y = 0; y < 5; y++) {
+    const row: boolean[] = [];
+    for (let x = 0; x < 3; x++) {
+      const byteIdx = 2 + y * 3 + x;
+      row.push(bytes[byteIdx % bytes.length] > 128);
+    }
+    // Mirror: col 3 = col 1, col 4 = col 0
+    grid.push([row[0], row[1], row[2], row[1], row[0]]);
+  }
+
+  // Render SVG
+  const cellSize = size / 5;
+  const r = size * 0.12; // border radius
+  let rects = "";
+  for (let y = 0; y < 5; y++) {
+    for (let x = 0; x < 5; x++) {
+      if (grid[y][x]) {
+        rects += `<rect x="${x * cellSize}" y="${y * cellSize}" width="${cellSize}" height="${cellSize}" fill="${fg}"/>`;
+      }
+    }
+  }
+
+  const svg = `<svg xmlns="http://www.w3.org/2000/svg" width="${size}" height="${size}" viewBox="0 0 ${size} ${size}">
+    <rect width="${size}" height="${size}" rx="${r}" fill="${bg}"/>
+    ${rects}
+  </svg>`;
+
+  return `data:image/svg+xml,${encodeURIComponent(svg)}`;
+}
+
+/**
+ * Create an <img> element with the identicon.
+ * Click copies the fingerprint to clipboard.
+ */
+export function createIdenticonEl(
+  fingerprint: string,
+  size: number = 36,
+  clickToCopy: boolean = true
+): HTMLImageElement {
+  const img = document.createElement("img");
+  img.src = generateIdenticon(fingerprint, size);
+  img.width = size;
+  img.height = size;
+  img.style.borderRadius = `${size * 0.12}px`;
+  img.style.cursor = clickToCopy ? "pointer" : "default";
+  img.title = fingerprint;
+
+  if (clickToCopy && fingerprint) {
+    img.addEventListener("click", (e) => {
+      e.stopPropagation();
+      navigator.clipboard.writeText(fingerprint).then(() => {
+        img.style.outline = "2px solid #4ade80";
+        setTimeout(() => {
+          img.style.outline = "";
+        }, 600);
+      });
+    });
+  }
+
+  return img;
+}

desktop/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "allowImportingTsExtensions": true,
+    "noEmit": true
+  },
+  "include": ["src"]
+}

desktop/vite.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig } from "vite";
+
+export default defineConfig({
+  clearScreen: false,
+  server: {
+    port: 1420,
+    strictPort: true,
+  },
+  envPrefix: ["VITE_", "TAURI_"],
+  build: {
+    target: "esnext",
+    minify: !process.env.TAURI_DEBUG ? "esbuild" : false,
+    sourcemap: !!process.env.TAURI_DEBUG,
+  },
+});

docs/BRANCH-android-rewrite.md

@@ -1,139 +0,0 @@
-# Branch: `android-rewrite`
-
-Pivot away from the legacy Kotlin + JNI Android client to a pure-Rust **Tauri 2.x Mobile** app that shares the same frontend and backend code as the desktop client.
-
-## Why this branch exists
-
-The Kotlin + JNI stack was a crash factory. Every failure mode we hit was at the Kotlin ↔ Rust boundary, and each fix uncovered the next layer of the onion:
-
-| Symptom | Root cause | Fix |
-|---|---|---|
-| App crashed on launch before `onCreate` returned | `__init_tcb` / `pthread_create` bionic private symbols leaking out of `libwzp_android.so` because the Rust crate used `crate-type = ["cdylib", "staticlib"]`. rust-lang/rust#104707 documents that staticlib alongside cdylib leaks non-exported symbols from the staticlib into the cdylib, and Bionic's private internal pthread symbols got bound LOCALLY inside our `.so` instead of resolved against `libc.so` at `dlopen` time | Dropped `staticlib` from the crate-type list. `crate-type = ["cdylib", "rlib"]` only. |
-| Stack overflow on `place_call` | `Dispatchers.IO` threads have a ~512 KB stack, too small for the Rust signal-connect path that does TLS handshake + quinn setup inside one closure | Launched JNI calls from a dedicated `java.lang.Thread` with an explicit 8 MB stack |
-| `ring` / `libcrypto` TLS reuse crash on second call | tokio runtime got dropped between calls, but `ring` keeps a TLS-stored SSL context that is invalidated when the runtime thread is reused by a new runtime — `ring` sees stale context and segfaults | Single long-lived tokio runtime for the entire signal client lifetime; split `start()` into an inline `connect+register` path and a `run()` path on a separate thread to avoid the `thread::spawn` closure's stack overflow |
-| Null dereference on register with fresh install | Identity seed file empty when it existed-but-was-blank, Rust side deref'd the zero-length slice | Generate seed if empty on register |
-
-Every fix kept the app limping along but the fundamental design problem remained: **state management was split across a Kotlin ViewModel and a Rust engine, with a hand-rolled JNI bridge in between that had to be perfect to not crash**. The working desktop Tauri client (with the same Rust backend) had none of these problems because it spoke to the Rust code via in-process `invoke()` from a WebView, not JNI.
-
-So: rewrite the Android app as a **Tauri 2.x Mobile app**, reusing the entire desktop codebase verbatim (`main.ts`, `style.css`, `index.html`, `main.rs`, `engine.rs` — everything). Tauri Mobile added Android support in v2, it's production-ready, and it eliminates the JNI boundary entirely.
-
-The incident postmortem lives at [`docs/incident-tauri-android-init-tcb.md`](incident-tauri-android-init-tcb.md).
-
-## Architecture
-
-```
-┌─────────────────────────────────────────────────┐
-│                Tauri 2.x Mobile                  │
-│                                                  │
-│  Android WebView  ──────────  HTML/JS/CSS       │  ← Shared with desktop
-│         │                      (main.ts)         │
-│         │                                        │
-│    invoke() ─────────────── Rust Commands       │  ← Shared with desktop
-│                             (main.rs)            │
-│                               │                  │
-│              ┌───────────────┼────────────┐     │
-│              │               │            │     │
-│         SignalMgr        CallEngine   Identity  │  ← Shared crates
-│        (signal_hub)     (wzp-client) (wzp-crypto)│
-│              │               │                  │
-│              │               │                  │
-│              ▼               ▼                  │
-│        QUIC to relay    Oboe audio (Android)    │
-│                         via wzp-native cdylib   │
-└─────────────────────────────────────────────────┘
-```
-
-**What is reused from desktop verbatim** (zero rewrite):
-
-- `desktop/src/main.ts` — entire frontend
-- `desktop/src/style.css` — all styling
-- `desktop/src/identicon.ts` — identicon rendering
-- `desktop/index.html` — HTML structure
-- `desktop/src-tauri/src/main.rs` — all Tauri commands (`connect`, `disconnect`, `register_signal`, `place_call`, …)
-- `desktop/src-tauri/src/engine.rs` — `CallEngine` wrapper
-
-**What is Android-specific**:
-
-- `desktop/src-tauri/src/android_audio.rs` — JVM-side audio routing (`AudioManager.setSpeakerphoneOn` for earpiece/speaker toggle). Runs from Tauri's existing JNI context — no hand-rolled bridge, Tauri owns the JVM hookup.
-- `desktop/src-tauri/src/wzp_native.rs` — runtime `dlopen` of `libwzp_native.so`, a standalone cdylib crate (`crates/wzp-native`) that owns all C++ (Oboe bridge). Kept in its own crate so its C/C++ static archives never get statically linked into `wzp-desktop`'s `.so`, which would re-trigger the `__init_tcb` / pthread leak.
-- `crates/wzp-native/` — the standalone C++/Oboe bridge cdylib. Loaded via `libloading` at runtime from `wzp_native.rs`. Provides capture + playout streams using Oboe's `Usage::VoiceCommunication` + `MODE_IN_COMMUNICATION` combo.
-- Android-specific target dependencies in `desktop/src-tauri/Cargo.toml` (`jni`, `ndk-context`, `libloading`) — no CPAL, no VPIO.
-
-## Key architectural decisions
-
-### 1. `wzp-native` as a standalone cdylib loaded via `libloading`
-
-The alternative — linking `wzp-native` as a regular Rust dep with C++ static archives — would cause the same `__init_tcb` crash that killed the Kotlin version. By making `wzp-native` its own cdylib and `dlopen`-ing it at runtime, Bionic's `libc.so` resolves every symbol at load time the way it's supposed to, and no private TCB symbols leak.
-
-### 2. `crate-type = ["cdylib", "rlib"]` only (no `staticlib`)
-
-Same reason. The `rlib` output is needed so the `wzp-desktop` binary target can link against the library; `cdylib` is needed for Android's `System.loadLibrary`; `staticlib` would reintroduce the symbol-leak bug.
-
-### 3. Oboe audio config
-
-`Usage::VoiceCommunication` + Java-side `MODE_IN_COMMUNICATION`. **Never** call `setAudioApi(AAudio)` explicitly — on some devices (Nothing Phone in particular) it causes Oboe to open the wrong stream type and audio goes silent. Let Oboe pick the audio API automatically. This is documented in the auto-memory `project_tauri_android_audio.md`.
-
-### 4. Speaker/earpiece toggle uses `tokio::task::spawn_blocking`
-
-Oboe's `stop()` + `start()` cycle is synchronous and can block for 50–200 ms. Calling it on the tokio executor stalls every other async task (including the QUIC datagram loop), dropping audio packets. Wrapping the toggle in `spawn_blocking` isolates it to a dedicated thread pool. Fixed in commit `76a4c53`.
-
-## Build pipeline
-
-Docker on SepehrHomeserverdk, same pattern as the Android legacy pipeline and the Windows pipeline:
-
-```
-./scripts/build-tauri-android.sh         # Full: pull + build + ntfy + rustypaste
-./scripts/build-tauri-android.sh --pull  # Explicit git pull (default)
-./scripts/build-tauri-android.sh --clean # Blow away the Rust target cache
-```
-
-**Image**: `wzp-android-builder` (shared with the legacy Kotlin pipeline). The Dockerfile was extended to install Node.js 20 LTS, Android API level 36, build-tools 35.0.0, tauri-cli 2.x, and all four Android Rust targets on top of the legacy NDK 26.1 + cargo-ndk + Gradle setup. Both pipelines coexist in the same image.
-
-**Output**: `wzp-release.apk` uploaded to rustypaste, URL delivered via `ntfy.sh/wzp`.
-
-## Known quirks (Tauri Mobile specific)
-
-1. **tauri-cli `android init` writes absolute paths** into `gradle.properties` for the NDK path. Those paths are local to wherever `android init` was run, so they break any cross-machine build unless overridden with `ANDROID_NDK_HOME` at build time. The build script exports `ANDROID_NDK_HOME` explicitly to work around this.
-
-2. **API 36 vs API 34 coexistence**: the legacy Kotlin pipeline targets API 34, Tauri Mobile 2.x wants compileSdk 36. The shared Docker image installs both SDK levels so neither pipeline needs to reinstall.
-
-3. **Identity seed lives in Android-specific app data dir**: `/data/data/com.wzp.phone/files/.wzp/identity` instead of `$HOME/.wzp/identity`. The shared `load_or_create_seed()` function in `desktop/src-tauri/src/lib.rs` uses Tauri's `app_data_dir()` which resolves correctly on both Android and desktop — no per-platform code needed.
-
-4. **Direct calls on macOS previously hit an identity mismatch bug** — the `CallEngine` was using `$HOME/.wzp/identity` directly while `register_signal` used Tauri's `app_data_dir()`. Fixed by routing both through `load_or_create_seed()` (commit `2fd9465`). This was important for cross-platform consistency.
-
-## Current state (snapshot)
-
-What works:
-
-- Tauri Mobile scaffold builds and runs on Android
-- Signal hub connect + register works
-- Room mode (SFU group calls) works with Oboe audio
-- Direct 1:1 calls work with full parity to desktop
-- Speaker/earpiece toggle works without stalling the audio pipeline
-- Call history, recent contacts, deregister UI all present (inherited from desktop)
-
-What remains (task list refs in parens):
-
-- Background service for keeping signal alive when app is backgrounded (#19)
-- Proper permission requests (microphone, notifications) on first launch (#19)
-- Incoming call notification while backgrounded (#19)
-- App icon + splash screen (#19)
-
-## Testing
-
-- **Build**: `./scripts/build-tauri-android.sh` — verify the APK lands on rustypaste and installs on device.
-- **Smoke test**: Install → open app → Register → Place call → Receive call. No crashes, audio flows both ways.
-- **Speaker toggle**: During a call, toggle speaker/earpiece several times in rapid succession. Audio should never stop, and the toggle should respond within ~200 ms.
-- **Stress test**: Call for 10+ minutes continuous. No memory growth, no packet loss beyond what's attributable to the network.
-
-## Files of interest
-
-| Path | Purpose |
-|---|---|
-| `desktop/src-tauri/src/lib.rs` | Shared Tauri commands (desktop + Android) |
-| `desktop/src-tauri/src/android_audio.rs` | JVM-side speaker/earpiece routing |
-| `desktop/src-tauri/src/wzp_native.rs` | Runtime dlopen of libwzp_native.so |
-| `crates/wzp-native/` | Standalone C++/Oboe cdylib, loaded at runtime |
-| `scripts/build-tauri-android.sh` | Remote Docker build pipeline |
-| `scripts/Dockerfile.android-builder` | Shared Android Docker image (legacy + Tauri) |
-| `docs/incident-tauri-android-init-tcb.md` | Postmortem of the Kotlin+JNI crash cascade |

docs/BRANCH-desktop-audio-rewrite.md

@@ -0,0 +1,164 @@
+# Branch: `feat/desktop-audio-rewrite`
+
+Home of the Tauri desktop client for macOS, Windows, and Linux. Named "audio-rewrite" because the original driver was replacing a CPAL-only audio pipeline with platform-native backends that support OS-level echo cancellation (VoiceProcessingIO on macOS, WASAPI Communications on Windows), but the branch has grown into the full desktop story — Windows cross-compilation, vendored dependencies, history UI, direct calling, the whole thing.
+
+## Purpose
+
+The desktop client shares 100% of its frontend (`desktop/src/`) and Tauri command layer (`desktop/src-tauri/src/lib.rs`, `engine.rs`, `history.rs`) with the Android build on `android-rewrite`. Differences are limited to:
+
+- **Audio backends**, which are platform-gated via Cargo target-dep sections in `desktop/src-tauri/Cargo.toml` and feature flags in `crates/wzp-client/Cargo.toml`.
+- **Identity storage paths**, which resolve via Tauri's `app_data_dir()` (`~/Library/Application Support/…` on macOS, `%APPDATA%\…` on Windows, `~/.local/share/…` on Linux).
+- **Build toolchains**: native `cargo build` on macOS/Linux, `cargo xwin` cross-compile from Linux for Windows via Docker on SepehrHomeserverdk.
+
+## Audio backend matrix
+
+| Target | Capture | Playback | AEC |
+|---|---|---|---|
+| macOS | CPAL (WASAPI/CoreAudio via cpal crate) OR VoiceProcessingIO (native Core Audio) | CPAL | VoiceProcessingIO native AEC (when `vpio` feature enabled) |
+| Windows (default) | CPAL → WASAPI shared mode | CPAL → WASAPI shared mode | None |
+| Windows (AEC build) | Direct WASAPI with `IAudioClient2::SetClientProperties(AudioCategory_Communications)` | CPAL → WASAPI shared mode | **OS-level**: Windows routes the capture stream through the driver's communications APO chain (AEC + NS + AGC) |
+| Linux | CPAL → ALSA/PulseAudio | CPAL → ALSA/PulseAudio | None |
+
+The macOS VPIO path is gated behind the `vpio` feature in `wzp-client` and the `coreaudio-rs` dep is itself `cfg(target_os = "macos")`, so enabling the feature on Windows or Linux is a no-op.
+
+The Windows AEC path is gated behind the `windows-aec` feature, also target-gated (the `windows` crate dep is only pulled in on Windows), and re-exports `WasapiAudioCapture as AudioCapture` when enabled so downstream code doesn't need to know which backend is active. The current Windows build at `target/windows-exe/wzp-desktop.exe` has `windows-aec` on; a baseline noAEC build is preserved at `target/windows-exe/wzp-desktop-noAEC.exe` for A/B comparison on real hardware.
+
+See [`BRANCH-android-rewrite.md`](BRANCH-android-rewrite.md) for Oboe audio on Android, which is its own story.
+
+## Recent major work
+
+### 1. Desktop direct calling feature (commit `2fd9465` and neighbors)
+
+Brought direct 1:1 calls to macOS with full parity to the Android client:
+
+- **Identity path fix**: the desktop `CallEngine::start` was loading seed from `$HOME/.wzp/identity` while `register_signal` used Tauri's `app_data_dir()`, producing two different fingerprints per run. Both now route through `load_or_create_seed()` which uses `app_data_dir()` everywhere.
+- **Call history with dedup**: `history.rs` stores a `Vec<CallHistoryEntry>` with a `CallDirection` enum (`Placed | Received | Missed`). The `log` function dedupes by `call_id` so an outgoing call isn't logged twice as "missed" (when the signal loop's `DirectCallOffer` handler fires) and then again as "placed" (when `place_call` returns). Instead the entry is updated in place.
+- **Recent contacts row**: a horizontal chip UI in the direct-call panel showing the last N peers with friendly aliases, clickable to re-dial.
+- **Deregister button**: lets a user drop their signal registration without quitting the app, useful when switching identities.
+- **Random alias derivation**: a new client sees a human-friendly alias like "silent-forest-41" derived deterministically from its seed, so it's identifiable in the UI before manual naming.
+- **Default room "general"** instead of "android", since the desktop client is not Android.
+
+### 2. macOS VoiceProcessingIO integration
+
+`crates/wzp-client/src/audio_vpio.rs` — a native Core Audio implementation using `AUGraph` + `AudioComponentInstance` with the VPIO audio unit. Gives you hardware-accelerated AEC (same AEC Apple ships in FaceTime / iMessage audio / voice memos) at the cost of tight coupling to Apple frameworks. Lock-free ring pattern matches the CPAL path so the upper layers don't notice the difference.
+
+Enabled by `features = ["audio", "vpio"]` in the macOS target section of `desktop/src-tauri/Cargo.toml`.
+
+### 3. Windows cross-compilation via cargo-xwin
+
+Cross-compiling Rust + Tauri to `x86_64-pc-windows-msvc` from Linux using `cargo-xwin`, which downloads the Microsoft CRT + Windows SDK on demand and drives `clang-cl` as the compiler. No Windows machine is needed for the build itself — only for runtime testing.
+
+**Build infrastructure**:
+
+- `scripts/Dockerfile.windows-builder` — Debian bookworm + Rust + cargo-xwin + Node 20 + cmake + ninja + llvm + clang + lld + nasm. Pre-warms the xwin MSVC CRT cache at image build time (saves ~4 minutes per cold build).
+- `scripts/build-windows-docker.sh` — fire-and-forget remote build via Docker on SepehrHomeserverdk. Same pattern as `build-tauri-android.sh`. Uploads the `.exe` to rustypaste and fires an `ntfy.sh/wzp` notification on start and on completion.
+- `scripts/build-windows-cloud.sh` — alternative pipeline using a temporary Hetzner Cloud VPS. Slower (full VM spin-up), more expensive, but useful when Docker image rebuilds would be disruptive.
+
+**Two critical blockers resolved** on the way to a working `.exe`:
+
+1. **libopus SSE4.1 / SSSE3 intrinsic compile failure**. `audiopus_sys` vendors libopus 1.3.1, whose `CMakeLists.txt` gates the per-file `-msse4.1` `COMPILE_FLAGS` behind `if(NOT MSVC)`. Under `clang-cl`, CMake sets `MSVC=1` (because `CMAKE_C_COMPILER_FRONTEND_VARIANT=MSVC` triggers `Platform/Windows-MSVC.cmake` which unconditionally sets the variable), so the per-file flag is never set and the SSE4.1 source files compile without the target feature — then fail with 20+ "always_inline function '_mm_cvtepi16_epi32' requires target feature 'sse4.1'" errors.
+
+   Fixed by **vendoring audiopus_sys into `vendor/audiopus_sys/`** and patching its bundled libopus to introduce an `MSVC_CL` variable that is true only for real `cl.exe` (distinguished via `CMAKE_C_COMPILER_ID STREQUAL "MSVC"`). The eight `if(NOT MSVC)` SIMD guards are flipped to `if(NOT MSVC_CL)` and the global `/arch` block at line 445 becomes `if(MSVC_CL)`, so clang-cl gets the GCC-style per-file flags while real cl.exe keeps the `/arch:AVX` / `/arch:SSE2` globals.
+
+   Wired in via `[patch.crates-io] audiopus_sys = { path = "vendor/audiopus_sys" }` at the workspace root.
+
+   Upstream tracking: [xiph/opus#256](https://github.com/xiph/opus/issues/256), [xiph/opus PR #257](https://github.com/xiph/opus/pull/257) (both stale).
+
+2. **tauri-build needs `icons/icon.ico` for the Windows PE resource**. The desktop only had `icon.png`. Generated a multi-size ICO (16/24/32/48/64/128/256) from the existing placeholder via Pillow and committed it. Placeholder quality — real branded icons can replace it later.
+
+### 4. Windows `AudioCategory_Communications` capture path (task #24)
+
+`crates/wzp-client/src/audio_wasapi.rs` — direct WASAPI capture via `IMMDeviceEnumerator → IAudioClient2 → SetClientProperties` with `AudioCategory_Communications`. This tells Windows "this is a VoIP call" and Windows routes the capture stream through the driver's registered communications APO chain, which on most Win10/11 consumer hardware includes AEC, NS, and AGC.
+
+**Caveat**: quality is driver-dependent. On a machine with a good communications APO (Intel Smart Sound, Dolby, modern Realtek on Win11 24H2+, anything with Voice Clarity enabled) it's excellent. On generic class-compliant drivers with no communications APO registered, it's a no-op. For a guaranteed AEC regardless of driver, see task #26 which tracks implementing the classic Voice Capture DSP (`CLSID_CWMAudioAEC`) as a fallback.
+
+Gated behind the `windows-aec` feature in `wzp-client`. Enabled by default in the Windows target section of `desktop/src-tauri/Cargo.toml`.
+
+## Build pipelines
+
+### Native macOS / Linux
+
+```bash
+cd desktop
+npm install
+npm run build
+cd src-tauri
+cargo build --release --bin wzp-desktop
+```
+
+### Windows x86_64 via Docker on SepehrHomeserverdk
+
+```bash
+./scripts/build-windows-docker.sh                 # Full: pull + build + download
+./scripts/build-windows-docker.sh --no-pull       # Skip git fetch
+./scripts/build-windows-docker.sh --rust          # Force-clean Rust target
+./scripts/build-windows-docker.sh --image-build   # (Re)build the Docker image (fire-and-forget)
+```
+
+Output lands at `target/windows-exe/wzp-desktop.exe`. Both `wzp-desktop.exe` and `wzp-desktop-noAEC.exe` can coexist in that directory; the script writes `wzp-desktop.exe` so renaming the prior build to `-noAEC.exe` (or any other name) before rebuilding preserves it.
+
+### Windows x86_64 via Hetzner Cloud (alternative)
+
+```bash
+./scripts/build-windows-cloud.sh                  # Full: create VM → build → download → destroy
+./scripts/build-windows-cloud.sh --prepare        # Create VM and install deps only
+./scripts/build-windows-cloud.sh --build          # Build on existing VM
+./scripts/build-windows-cloud.sh --destroy        # Delete the VM
+WZP_KEEP_VM=1 ./scripts/build-windows-cloud.sh    # Keep VM alive after build for debug
+```
+
+Remember to destroy the VM at end of day with `--destroy`.
+
+### Linux x86_64 (relay + CLI + bench)
+
+```bash
+./scripts/build-linux-docker.sh                   # Fire-and-forget remote Docker build
+./scripts/build-linux-docker.sh --install         # Wait for completion and download
+```
+
+Uses the same `wzp-android-builder` Docker image as Android (not a separate image), since the deps (Rust + cmake + ring prereqs) are the same.
+
+## Testing
+
+### Direct calling parity
+
+1. Build on two machines (macOS + Windows, or two macOS, or any combination).
+2. Both machines register on the same relay.
+3. Copy one machine's fingerprint into the other's direct-call panel.
+4. Place the call. Confirm ringing UI on the callee and "calling…" UI on the caller.
+5. Answer. Confirm audio flows both ways.
+6. Hang up from either side. Confirm call-history entries are labeled correctly (`Outgoing` on caller, `Incoming` on callee, never `Missed` on a successful call).
+
+### Windows AEC A/B
+
+1. Install `wzp-desktop-noAEC.exe` and `wzp-desktop.exe` on the same Windows box.
+2. Join a call from each (separately) while a second machine plays known audio through the first machine's speakers.
+3. On the remote (listening) side: the `noAEC` call should have clear audible echo; the AEC call should have minimal or no echo after a 1–2 s convergence period.
+4. If both builds sound identical (with echo) → the `AudioCategory_Communications` switch isn't triggering the driver's APO chain. Investigate via task #26 (Voice Capture DSP fallback).
+
+## Known quirks
+
+1. **libopus vendor path is workspace-relative**. `[patch.crates-io] audiopus_sys = { path = "vendor/audiopus_sys" }` works from any crate in the workspace because Cargo resolves it against the root `Cargo.toml`'s directory. If the workspace is moved or vendored into another workspace, update the path.
+
+2. **`cargo xwin` overwrites `override.cmake` on every invocation**. Any attempt to patch `~/.cache/cargo-xwin/cmake/clang-cl/override.cmake` at Docker image build time is inert because `src/compiler/clang_cl.rs` line ~444 writes the bundled file fresh on every run. All real fixes must land in the source tree (via the vendored audiopus_sys, as done here), not in the cargo-xwin cache.
+
+3. **WebView2 runtime is a prerequisite on Windows 10**. Windows 11 ships with it. If the `.exe` launches and immediately exits with no error on a Win10 machine, that's the missing runtime — install it from [Microsoft's Evergreen bootstrapper](https://developer.microsoft.com/en-us/microsoft-edge/webview2/).
+
+4. **Rust 2024 edition `unsafe_op_in_unsafe_fn` lint**. The WASAPI backend in `audio_wasapi.rs` emits ~18 of these warnings because Rust 2024 requires explicit `unsafe { ... }` blocks inside `unsafe fn` bodies. The warnings don't block the build and don't affect runtime behavior; cleaning them up is tracked informally as tech debt.
+
+## Files of interest
+
+| Path | Purpose |
+|---|---|
+| `desktop/src/` | Shared frontend (TypeScript + HTML + CSS) |
+| `desktop/src-tauri/src/lib.rs` | Tauri commands shared with Android |
+| `desktop/src-tauri/src/engine.rs` | `CallEngine` wrapper |
+| `desktop/src-tauri/src/history.rs` | Persistent call history store with dedup |
+| `crates/wzp-client/src/audio_io.rs` | CPAL capture + playback (baseline) |
+| `crates/wzp-client/src/audio_vpio.rs` | macOS VoiceProcessingIO capture (AEC) |
+| `crates/wzp-client/src/audio_wasapi.rs` | Windows WASAPI communications capture (AEC) |
+| `vendor/audiopus_sys/opus/CMakeLists.txt` | Patched libopus for clang-cl SIMD |
+| `scripts/Dockerfile.windows-builder` | Windows cross-compile Docker image |
+| `scripts/build-windows-docker.sh` | Remote Docker build pipeline |
+| `scripts/build-windows-cloud.sh` | Hetzner VPS alternative pipeline |
+| `scripts/build-linux-docker.sh` | Linux x86_64 relay/CLI build pipeline |

docs/PRD-desktop-direct-calling.md

@@ -1,22 +0,0 @@
-# PRD: Desktop Direct Calling — Backport SignalManager
-
-## Problem
-
-The desktop Tauri app has the direct calling UI (Room/Direct Call toggle, Register, Call buttons) but the backend uses inline async code in `main.rs` instead of a proper `SignalManager`. This needs to be backported from the Android refactor.
-
-## Tasks
-
-1. **Create `signal_mgr.rs` for desktop** — same pattern as Android, or reuse the crate directly
-2. **Wire into Tauri commands** — `register_signal` should use `SignalManager::connect()` + `run_recv_loop()` on a dedicated thread
-3. **State polling** — `get_signal_status` should call `SignalManager::get_state_json()`
-4. **place_call / answer_call** — delegate to SignalManager methods
-5. **Merge android branch into desktop branch** — resolve the 37 desktop-only + 90 android-only commit divergence
-6. **Test** — Android calls Desktop, Desktop calls Android
-
-## UI Fixes
-
-1. **Default alias** — generate random name on first start (like Android does)
-2. **Default room** — change from "android" to "general"
-3. **Fingerprint display** — ensure full `xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx` format (not truncated)
-4. **Deregister button** — ability to disconnect signal channel
-5. **Call state reset** — after hangup, return to "Registered" state, not stuck on "Ringing"

docs/PRD-local-recording.md

@@ -0,0 +1,141 @@
+# PRD: Local Recording + Cloud Mixer for Podcast-Quality Interviews
+
+## Problem
+
+WarzonePhone delivers real-time encrypted voice, but the audio quality is limited by network conditions (codec compression, packet loss, jitter). Podcasters and interviewers need pristine, studio-grade recordings of each participant — independent of what the network delivers.
+
+## Solution
+
+**Dual-path architecture**: each client simultaneously (1) participates in the live call at whatever codec quality the network supports, and (2) records their own microphone locally as lossless PCM. After the session, all local recordings are uploaded to a self-hosted mixer service that aligns, normalizes, and outputs a final multi-track or mixed file.
+
+## Architecture
+
+```
+                          ┌──────────────────┐
+  Mic ──┬── Opus/Codec2 ──► Network (live)   │  ← real-time call
+        │                 └──────────────────┘
+        │
+        └── WAV 48kHz ────► Local File        │  ← pristine recording
+                           (timestamped)
+                              │
+                              ▼ (after hangup)
+                          ┌──────────────────┐
+                          │  Mixer Service    │  ← self-hosted
+                          │  (align + mix)    │
+                          └──────────────────┘
+                              │
+                              ▼
+                          Final MP3/WAV/FLAC
+```
+
+## Requirements
+
+### Phase 1: Local Recording (MVP)
+
+**All clients (Desktop, Android, Web):**
+
+1. **Record toggle**: User can enable "Record this call" before or during a call
+2. **Recording pipeline**: Tap raw PCM from the microphone capture path *before* it enters the codec encoder
+3. **File format**: WAV (48kHz, 16-bit, mono) — simple, universally supported, lossless
+4. **Sync markers**: Embed a monotonic timestamp (ms since call start) at the beginning of the recording, and periodically (every 10s) write a sync marker packet into a sidecar JSON file:
+   ```json
+   {"ts_ms": 30000, "seq": 1500, "wall_clock_utc": "2026-04-07T12:00:30Z"}
+   ```
+   This allows the mixer to align recordings from different participants even if they join at different times.
+5. **Storage**:
+   - Desktop: `~/.wzp/recordings/{room}_{timestamp}.wav`
+   - Android: `Documents/WarzonePhone/{room}_{timestamp}.wav`
+   - Web: IndexedDB blob or File System Access API
+6. **File size estimate**: 48kHz * 16-bit * mono = 96 KB/s = ~5.6 MB/min = ~345 MB/hour
+7. **UI indicator**: Red dot + timer showing recording is active and file size growing
+8. **On hangup**: Close the WAV file, show "Recording saved" with file path/size
+
+### Phase 2: Upload to Mixer
+
+1. **Upload endpoint**: Self-hosted HTTP service (Rust or Go) that accepts WAV uploads with metadata
+2. **Chunked/resumable upload**: Large files need resumable uploads (tus protocol or simple chunked POST)
+3. **Upload metadata**:
+   ```json
+   {
+     "session_id": "uuid",
+     "participant_fingerprint": "xxxx:xxxx:...",
+     "alias": "Alice",
+     "room": "podcast-ep-42",
+     "duration_secs": 3600,
+     "sync_markers": [...],
+     "sample_rate": 48000,
+     "channels": 1,
+     "bit_depth": 16
+   }
+   ```
+4. **Upload UI**: Progress bar after hangup, option to upload now or later
+5. **Retry on failure**: Queue uploads for retry if network is unavailable
+
+### Phase 3: Mixer Service
+
+1. **Alignment**: Use sync markers (wall clock + sequence numbers) to align recordings from all participants to a common timeline
+2. **Silence trimming**: Detect and optionally trim leading/trailing silence
+3. **Normalization**: Per-track loudness normalization (LUFS-based)
+4. **Noise reduction**: Optional per-track noise gate or RNNoise pass
+5. **Output formats**:
+   - Multi-track: ZIP of individual WAVs (aligned, normalized)
+   - Mixed: Single stereo or mono WAV/MP3/FLAC with all participants
+   - Podcast-ready: Loudness-normalized to -16 LUFS (podcast standard)
+6. **Web UI**: Simple dashboard to see sessions, download outputs, preview waveforms
+7. **Self-hosted**: Docker image, single binary, SQLite for metadata
+
+## Implementation Notes
+
+### Recording tap point
+
+The recording must tap *after* AGC (so levels are normalized) but *before* the codec encoder (to avoid compression artifacts). In the current architecture:
+
+```
+Mic → Ring Buffer → AGC → [TAP HERE for recording] → Opus/Codec2 → Network
+```
+
+**Desktop** (`engine.rs`): After `capture_agc.process_frame()`, before `encoder.encode()`
+**Android** (`engine.rs`): Same location — after AGC, before encode
+**CLI** (`call.rs`): After `self.agc.process_frame()` in `CallEncoder::encode_frame()`
+
+### WAV writer
+
+Use a simple streaming WAV writer that:
+- Writes the WAV header with placeholder data length
+- Appends PCM samples as they come
+- On close, seeks back to update the data length in the header
+
+### Sync mechanism
+
+Wall-clock UTC alone is insufficient (clocks drift). The sync strategy:
+1. Each participant records their local monotonic time + wall clock at call start
+2. Periodically (every 10s), each participant writes: `{local_mono_ms, seq_number, utc_iso}`
+3. The mixer uses sequence numbers (which are shared via the wire protocol) as ground truth for alignment, with wall clock as a fallback
+
+### Privacy
+
+- Local recordings never leave the device without explicit user action
+- Upload is manual, not automatic
+- The mixer service processes files and can delete originals after mixing
+- No recording data flows through the relay — only the user's own mic
+
+## Non-Goals (v1)
+
+- Live transcription (future)
+- Video recording (audio only)
+- Automatic upload without user consent
+- Recording other participants' audio (only your own mic)
+- Real-time mixing (post-session only)
+
+## Milestones
+
+| Phase | Scope | Effort |
+|-------|-------|--------|
+| 1a | Local WAV recording on Desktop | 1-2 days |
+| 1b | Local WAV recording on Android | 1-2 days |
+| 1c | Sync markers + metadata sidecar | 1 day |
+| 2a | Upload service (HTTP + storage) | 2-3 days |
+| 2b | Upload UI in clients | 1-2 days |
+| 3a | Mixer: alignment + normalization | 2-3 days |
+| 3b | Mixer: web dashboard | 2-3 days |
+| 3c | Docker packaging | 1 day |

docs/PRD-studio-quality.md

@@ -0,0 +1,56 @@
+# PRD: Studio Quality Tiers (Opus 32k/48k/64k)
+
+## Status: Implemented
+
+Studio quality tiers have been added to the wire protocol and all clients.
+
+## What Was Added
+
+### Wire Protocol (codec_id.rs)
+
+Three new `CodecId` variants using the 4-bit header space (values 6-8):
+
+| CodecId | Wire Value | Bitrate | Frame | Use Case |
+|---------|-----------|---------|-------|----------|
+| Opus32k | 6 | 32 kbps | 20ms | Studio low — noticeable improvement over 24k for voice |
+| Opus48k | 7 | 48 kbps | 20ms | Studio — excellent voice, captures nuance |
+| Opus64k | 8 | 64 kbps | 20ms | Studio high — near-transparent quality |
+
+### Quality Profiles
+
+| Profile | Codec | FEC | Bandwidth (with FEC) |
+|---------|-------|-----|---------------------|
+| STUDIO_32K | Opus 32k | 10% | ~35 kbps |
+| STUDIO_48K | Opus 48k | 10% | ~53 kbps |
+| STUDIO_64K | Opus 64k | 10% | ~70 kbps |
+
+FEC is set to 10% (vs 20% for GOOD) — studio assumes a good network.
+
+### Client Support
+
+| Client | Selection | Status |
+|--------|-----------|--------|
+| Desktop (Tauri) | Quality slider in Settings (8 levels) | Done |
+| CLI | `--profile studio-64k` / `studio-48k` / `studio-32k` | Done |
+| Android | Needs codec picker update in SettingsScreen.kt | TODO |
+| Web | Needs UI | TODO |
+
+### Cross-Codec Interop
+
+All decoder auto-switch paths (call.rs, desktop engine.rs) handle the new codec IDs. A studio-64k client can talk to a codec2-1200 client — the receiver auto-switches.
+
+## When to Use Studio Tiers
+
+- **Podcast recording sessions**: Use studio-64k for best quality (combined with local WAV recording for pristine output)
+- **Music collaboration**: Opus at 48-64k captures instrument harmonics much better than 24k
+- **Good network conditions**: Only useful when bandwidth isn't constrained; the extra bits are wasted on lossy networks
+
+## When NOT to Use
+
+- **Mobile data**: Stick with Auto/GOOD — studio tiers use 2-3x the bandwidth
+- **High packet loss**: Studio profiles use minimal FEC (10%); degraded networks need DEGRADED or CATASTROPHIC profiles with 50-100% FEC
+- **Large group calls**: Each participant's stream multiplies bandwidth; 64k * 10 participants = 640 kbps incoming
+
+## Backward Compatibility
+
+Old clients (before this change) will receive packets with CodecId 6/7/8 which they don't recognize. The `from_wire()` returns `None` for unknown values, causing the packet to be dropped. Old clients can still *send* to new clients fine (they use CodecId 0-5). This is acceptable for a pre-release protocol.

docs/incident-tauri-android-init-tcb.md

@@ -1,431 +0,0 @@
-# Incident report — Tauri Android `__init_tcb+4` SIGSEGV
-
-**Status:** Blocked. Reproducible crash with a known trigger at the cc::Build /
-rustc-link-lib layer that we cannot yet explain. Writing this report to hand
-off for external help.
-
-**Project:** WarzonePhone (Rust + Tauri 2.x Mobile) Android rewrite
-**Branch:** `feat/desktop-audio-rewrite`
-**Target phone:** Pixel 6 (`oriole`), Android 16 (`BP3A.250905.014`), arm64-v8a
-**Date range of investigation:** 2026-04-09 (one working session, ~27 builds)
-
----
-
-## One-paragraph summary
-
-We're porting the existing CPAL-backed desktop Tauri app (`desktop/src-tauri`)
-to Tauri Mobile Android so the same Rust + Tauri + WebView codebase runs on
-both platforms. The Android `.apk` launches, renders the home screen, and
-registers on a relay for signal-only builds (no audio backend). The moment
-we add **any** `cc::Build::new().cpp(true).cpp_link_stdlib("c++_shared")`
-call to `build.rs` — even with a 6-line cpp file that just returns 42 and is
-never called from Rust — the built `.so` crashes at launch inside
-`__init_tcb(bionic_tcb*, pthread_internal_t*)+4` via `pthread_create` via
-`std::thread::spawn` via `tao::ndk_glue::create` via
-`Java_com_wzp_desktop_WryActivity_create`, before our Rust entry point has
-a chance to run. The exact same NDK, exact same Rust toolchain, exact same
-Docker image is used by the legacy `wzp-android` crate (via `cargo-ndk`)
-which compiles Oboe and runs fine on the same phone.
-
----
-
-## Environment
-
-**Docker build image:** `wzp-android-builder` (Dockerfile at
-`scripts/Dockerfile.android-builder`)
-
-- Base: `debian:bookworm`
-- JDK 17
-- Android SDK:
-  - cmdline-tools latest
-  - `platforms;android-34`, `platforms;android-36`
-  - `build-tools;34.0.0`, `build-tools;35.0.0`
-  - `ndk;26.1.10909125` (last stable before scudo/MTE crash on NDK r27+)
-  - `platform-tools`
-- Node.js 20 LTS
-- Rust stable `1.94.1 (e408947bf 2026-03-25)`
-- Rust android targets: `aarch64-linux-android`, `armv7-linux-androideabi`,
-  `i686-linux-android`, `x86_64-linux-android`
-- `cargo-ndk` + `cargo tauri-cli 2.10.1` (latest 2.x)
-
-**Host:** Docker on `SepehrHomeserverdk` (remote build server).
-
-**Phone:** Pixel 6, Android 16, kernel 6.1.134-android14-11, on the same LAN
-as the build machine and a local `wzp-relay` binary.
-
-**Tauri crate:** `desktop/src-tauri/` in the workspace at the root of the
-repo. Depends on `tauri = "2"`, `tauri-plugin-shell = "2"`, `tokio`, `rustls`,
-`wzp-proto`, `wzp-codec`, `wzp-fec`, `wzp-crypto`, `wzp-transport`, and (on
-non-Android only) `wzp-client` with `features = ["audio", "vpio"]`. The
-crate's `[lib]` section is:
-
-```toml
-[lib]
-name = "wzp_desktop_lib"
-crate-type = ["staticlib", "cdylib", "rlib"]
-```
-
-The crate produces `libwzp_desktop_lib.so` which is `System.loadLibrary`'d by
-Tauri's generated `WryActivity.onCreate` via JNI.
-
----
-
-## The crash
-
-Every failing build produces the same stack at launch, same pc offsets:
-
-```
-signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0x00000072XXXXXX00f (write)
-
-#00 pc 000000000130cc74 libwzp_desktop_lib.so (__init_tcb(bionic_tcb*, pthread_internal_t*)+4)
-#01 pc 0000000001331cf0 libwzp_desktop_lib.so (pthread_create+360)
-#02 pc 00000000012bee04 libwzp_desktop_lib.so (std::sys::thread::unix::Thread::new::h87be8e9feeaaaf84+184)
-#03 pc 0000000000e37f5c libwzp_desktop_lib.so (std::thread::lifecycle::spawn_unchecked::h941f828f9a95150d+1504)
-#04 pc 0000000000e461e8 libwzp_desktop_lib.so (std::thread::builder::Builder::spawn_unchecked::hec5f087680cb0248+112)
-#05 pc 0000000000e441c8 libwzp_desktop_lib.so (std::thread::functions::spawn::ha3d3fbf2d9fe53e3+108)
-#06 pc ...             libwzp_desktop_lib.so (tao::platform_impl::platform::ndk_glue::create::h254c68662718841a+1792)
-#07 pc ...             libwzp_desktop_lib.so (Java_com_wzp_desktop_WryActivity_create+76)
-```
-
-The offsets are **byte-identical across every failing build**, even when the
-cpp content changes drastically (cf. `cpp_smoke.cpp` at 6 lines, 20 lines,
-200+ Oboe source files). We believe this is because cargo caches the Rust
-compilation unit and only the build-script artifacts differ, and the final
-link produces the same layout.
-
-`__init_tcb` is defined locally inside our `.so` with C++ mangling:
-
-```
-_Z10__init_tcbP10bionic_tcbP18pthread_internal_t
-```
-
-It originates from bionic's `pthread_create.cpp`, which got pulled in
-statically from the NDK's `sysroot/usr/lib/aarch64-linux-android/libc.a`.
-Both failing and known-good (legacy `wzp_android.so`) builds contain this
-same static symbol — the presence of the symbol is not the problem.
-
-Fault address `0x72XXXXXX00f` with code `SEGV_ACCERR` (access permission
-error, write). Aligned to `+4` inside `__init_tcb`, which is typically a
-store into the passed-in `bionic_tcb*`. The pointer is either NULL-ish or
-pointing into read-only memory.
-
----
-
-## Bisection (the important part)
-
-We started from a known-good commit (`5309938`) where the Tauri Android app
-launches, registers on a relay, and behaves identically to the desktop app
-modulo audio. Then we added features **one variable at a time**:
-
-| Step | Commit | Change vs previous | Result |
-|---|---|---|---|
-| Baseline | `5309938` | — | ✅ launches, renders home, registers on relay |
-| **A** | `f96d7ce` | Add `cc = "1"` build-dep + compile trivial `cpp/hello.c` via `cc::Build` (C, not C++). Static lib never linked in. | ✅ |
-| **B** | `ae4f366` | Add `wzp-client` Android dep with `default-features = false` (no CPAL, no VPIO). No new imports. | ✅ |
-| **C** | `19fd3dd` | Un-cfg-gate `mod engine;` in `lib.rs` so `engine.rs` compiles on Android. `CallEngine::start()` has an Android stub returning an error. | ✅ |
-| **D** | `a852cad` | Compile `cpp/getauxval_fix.c` (legacy wzp-android shim). Still pure C. | ✅ |
-| **E** | `4250f1b` | **Compile full Oboe C++ bridge** (200+ source files from `google/oboe@1.8.1`). `cc::Build::new().cpp(true).std("c++17").cpp_link_stdlib(Some("c++_shared"))` + `-llog` + `-lOpenSLES` link directives. Nothing called from Rust yet — the `extern "C"` bridge functions are exported but never referenced from the Rust side. | ❌ **crash** |
-| E.4 | `aa240c6` | **Only change:** replace the entire Oboe compile with ONE tiny `cpp_smoke.cpp` file: `extern "C" int wzp_cpp_smoke(void) { std::lock_guard<std::mutex> lk(m); std::thread t([](){...}); t.join(); return g.load(); }`. Still `cpp(true) + cpp_link_stdlib("c++_shared")`. Drop `-llog`/`-lOpenSLES`. | ❌ **same crash, same offsets** |
-| E.2 | `0224ce6` | Shrink `cpp_smoke.cpp` further: just `std::atomic<int>` + `fetch_add`, no mutex, no thread, no includes beyond `<atomic>`. | ❌ **same crash, same offsets** |
-| E.1 | `0d74366` | **Absolute minimum:** `cpp_smoke.cpp` = `extern "C" int wzp_cpp_hello(void){return 42;}`. NO `#include`. NO STL. Just a function. Still compiled with `cpp(true) + cpp_link_stdlib("c++_shared")`. | ❌ **same crash, same offsets** |
-
-### Additional confirming observations
-
-1. **The cpp code is dead-stripped.** `llvm-nm -a libwzp_desktop_lib.so` shows
-   zero matches for `wzp_cpp_hello`, `wzp_cpp_smoke`, or any Oboe symbol in
-   builds E through E.1. The static archive (`libwzp_cpp_smoke.a` /
-   `liboboe_bridge.a`) exists on disk under
-   `target/aarch64-linux-android/debug/build/wzp-desktop-*/out/`, but because
-   nothing in Rust ever references the exported C function, the final linker
-   drops it.
-
-2. **`build.rs` link directives are the real delta.** `cc::Build::new()
-   .cpp(true).cpp_link_stdlib(Some("c++_shared"))` emits a
-   `cargo:rustc-link-lib=c++_shared` directive that adds a `NEEDED` entry for
-   `libc++_shared.so` to the final `.so`'s dynamic table. `readelf -d` on
-   the crashing `.so` shows:
-
-   ```
-   NEEDED       Shared library: [libc++_shared.so]
-   NEEDED       Shared library: [liblog.so]      (only in full Oboe build)
-   NEEDED       Shared library: [libOpenSLES.so] (only in full Oboe build)
-   ```
-
-   The working baseline `.so` has no `NEEDED` entries beyond libc/liblog.
-
-3. **Linker version doesn't matter.** We tried forcing
-   `aarch64-linux-android26-clang` as the linker (API 26 has proper dynamic
-   bindings to libc.so's runtime `pthread_create`/`__init_tcb`) via three
-   different mechanisms:
-   - `CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER` env var in `docker run`
-   - `.cargo/config.toml` workspace-level linker override
-   - **Binary replacement inside the image**: `mv
-     aarch64-linux-android24-clang .orig` and replace with a shell script
-     that `exec`s `aarch64-linux-android26-clang`. Verified by calling
-     `--version` which prints `Target: aarch64-unknown-linux-android26`.
-
-   All three made no difference. The `__init_tcb` symbol is pulled statically
-   from the **same** `libc.a` regardless of which clang wrapper is used — the
-   NDK ships ONE `libc.a` at
-   `sysroot/usr/lib/aarch64-linux-android/libc.a` shared across all API
-   levels. Only the per-API `libc.so` symlinks change (and we're linked
-   statically, not dynamically, against libc).
-
-4. **Legacy `wzp-android` crate works on the same phone, same image.** Run
-   in the exact same Docker container, the legacy Kotlin app's JNI library
-   (`crates/wzp-android` built via `cargo ndk`) compiles a subset of the
-   same Oboe code, produces a `.so` that has the same static
-   `_Z10__init_tcbP...` + `pthread_create` + `pthread_create.cpp` symbols,
-   and launches cleanly on the Pixel 6. Key differences between the two
-   build paths:
-
-   | | `wzp-android` (works) | `wzp-desktop` Tauri (crashes) |
-   |---|---|---|
-   | Build driver | `cargo ndk -t arm64-v8a build --release -p wzp-android` | `cargo tauri android build --debug --target aarch64 --apk` |
-   | Profile | release | debug (release crashes identically) |
-   | Linker | `aarch64-linux-android26-clang` (via `.cargo/config.toml` which cargo-ndk honors) | `aarch64-linux-android24-clang` (tauri-cli hardcodes and ignores config; the shim redirect makes no difference) |
-   | crate-type | `["cdylib", "rlib"]` | `["staticlib", "cdylib", "rlib"]` |
-   | JNI entrypoint | direct Kotlin `System.loadLibrary` + our own `native fun` declarations; first `pthread_create` runs later from the tokio runtime inside a command | `WryActivity.onCreate` via Tauri's generated Java glue; first `pthread_create` runs **inside the JNI call** via `tao::ndk_glue::create` |
-   | Other heavy deps | tokio, wzp-{proto,codec,fec,crypto,transport} | tokio, tauri, tauri-runtime-wry, tao, wry, webview2-com, soup3, webkit2gtk (all platform-specific ones cfg-gated out of android), and also all of the above |
-   | Binary size | `libwzp_android.so` ≈ 14 MB (release) | `libwzp_desktop_lib.so` ≈ 160 MB (debug), 16 MB (release) |
-
-5. **The crash happens in the JNI-callback thread during `onCreate`.** Frame
-   #06 `tao::platform_impl::platform::ndk_glue::create+1792` is tao's Android
-   event-loop bootstrap, which Tauri calls from inside
-   `Java_com_wzp_desktop_WryActivity_create` in response to the Java-side
-   activity lifecycle. This means the thread spawn is happening while the
-   Java VM still holds the native onCreate call, before `onCreate` has
-   returned to the Android runtime. Legacy `wzp-android` never spawns a
-   thread from an onCreate JNI call — it spawns threads only from
-   `nativeSignalConnect`/similar commands invoked later from Kotlin button
-   clicks, after the activity is fully initialised.
-
----
-
-## Current suspect
-
-One of the two items below, probably (2):
-
-1. **The `.cpp(true)` mode in cc-rs changes something invisible in the link
-   pipeline** (for example, emitting a different `-x` flag to clang, or
-   changing linker driver selection). We have not yet verified this by
-   diffing the actual rustc linker invocation between a working and a
-   crashing build with `--verbose` + `-Clink-arg=-Wl,-t`.
-
-2. **Adding `libc++_shared.so` as a NEEDED entry causes Android's dynamic
-   linker to load libc++_shared.so before our `.so`'s init runs, and
-   something in libc++_shared's `.init_array` interacts badly with
-   tao::ndk_glue's `pthread_create` call from inside the JNI onCreate
-   window**. The legacy crate doesn't hit this because (a) it has no
-   NEEDED libc++_shared when built without Oboe, and (b) even when it does
-   build Oboe, its thread spawns happen outside the onCreate JNI call so
-   whatever libc state is wrong at that moment is already stabilised.
-
-We have not yet confirmed (2) with the obvious A/B test: keep `cpp_smoke.cpp`
-but drop `.cpp_link_stdlib(Some("c++_shared"))` (and drop any manual
-`cargo:rustc-link-lib=c++_shared`) so the NEEDED entry disappears but the
-rest of the pipeline stays identical. That's the next experiment we were
-going to run, but the user reasonably asked for this report first.
-
----
-
-## What we've ruled out
-
-- **NDK API level** — forcing API-26 linker via three independent mechanisms
-  made zero difference.
-- **Build profile** — release (`0x6b8000` offset, 21 MB unsigned APK) and
-  debug (same 193 MB APK, same crash offsets) both crash identically.
-- **Oboe specifically** — replacing the Oboe compile with 6 lines of C++
-  that does nothing still reproduces the crash.
-- **cpp code being executed at runtime** — dead-stripped, not in the final
-  `.so` at all per `nm -a`.
-- **minSdk in build.gradle** — bumped from 24 to 26, no effect.
-- **libdl.a stub issue** — ruled out via logcat (`libdl.a is a stub --- use
-  libdl.so instead` was only surfacing from our own `dlsym` shim that we
-  subsequently deleted).
-- **`pthread_create` interposition via `-Wl,--wrap=pthread_create`** — tried
-  and reverted; the wrap target still resolved to the broken static stub.
-- **Keystore / signing** — debug signing with persistent `~/.android/
-  debug.keystore` works fine; no signature mismatch issues.
-
----
-
-## The files involved
-
-### `desktop/src-tauri/build.rs` (current state, E.1)
-
-```rust
-use std::path::PathBuf;
-use std::process::Command;
-
-fn main() {
-    // Embedded git hash
-    let git_hash = Command::new("git")
-        .args(["rev-parse", "--short", "HEAD"])
-        .output()
-        .ok()
-        .filter(|o| o.status.success())
-        .and_then(|o| String::from_utf8(o.stdout).ok())
-        .map(|s| s.trim().to_string())
-        .unwrap_or_else(|| "unknown".into());
-    println!("cargo:rustc-env=WZP_GIT_HASH={git_hash}");
-    println!("cargo:rerun-if-changed=../../.git/HEAD");
-    println!("cargo:rerun-if-changed=../../.git/refs/heads");
-
-    let target = std::env::var("TARGET").unwrap_or_default();
-    if target.contains("android") {
-        // Step A: plain C sanity file
-        println!("cargo:rerun-if-changed=cpp/hello.c");
-        cc::Build::new().file("cpp/hello.c").compile("wzp_hello");
-
-        // Step D: legacy getauxval shim
-        println!("cargo:rerun-if-changed=cpp/getauxval_fix.c");
-        cc::Build::new().file("cpp/getauxval_fix.c").compile("getauxval_fix");
-
-        // Step E.1: minimal C++ smoke — THIS STEP BRINGS BACK THE CRASH
-        println!("cargo:rerun-if-changed=cpp/cpp_smoke.cpp");
-        cc::Build::new()
-            .cpp(true)
-            .std("c++17")
-            .cpp_link_stdlib(Some("c++_shared"))
-            .file("cpp/cpp_smoke.cpp")
-            .compile("wzp_cpp_smoke");
-
-        // Copy libc++_shared.so into gen/android jniLibs so the runtime
-        // linker can find it when the NEEDED entry fires.
-        if let Ok(ndk) = std::env::var("ANDROID_NDK_HOME").or_else(|_| std::env::var("NDK_HOME")) {
-            let triple = "aarch64-linux-android";
-            let abi = "arm64-v8a";
-            let lib_dir = format!(
-                "{ndk}/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/{triple}"
-            );
-            println!("cargo:rustc-link-search=native={lib_dir}");
-            let shared_so = format!("{lib_dir}/libc++_shared.so");
-            if std::path::Path::new(&shared_so).exists() {
-                let manifest = std::env::var("CARGO_MANIFEST_DIR").unwrap_or_default();
-                let jni_dir = format!("{manifest}/gen/android/app/src/main/jniLibs/{abi}");
-                if std::fs::create_dir_all(&jni_dir).is_ok() {
-                    let _ = std::fs::copy(&shared_so, format!("{jni_dir}/libc++_shared.so"));
-                }
-            }
-        }
-    }
-
-    tauri_build::build()
-}
-```
-
-### `desktop/src-tauri/cpp/cpp_smoke.cpp` (E.1)
-
-```cpp
-extern "C" int wzp_cpp_hello(void) {
-    return 42;
-}
-```
-
-### `desktop/src-tauri/Cargo.toml` (relevant excerpts)
-
-```toml
-[package]
-name = "wzp-desktop"
-version = "0.1.0"
-edition = "2024"
-
-[lib]
-name = "wzp_desktop_lib"
-crate-type = ["staticlib", "cdylib", "rlib"]
-
-[[bin]]
-name = "wzp-desktop"
-path = "src/main.rs"
-
-[build-dependencies]
-tauri-build = { version = "2", features = [] }
-cc = "1"
-
-[dependencies]
-tauri = { version = "2", features = [] }
-tauri-plugin-shell = "2"
-serde = { version = "1", features = ["derive"] }
-serde_json = "1"
-tokio = { version = "1", features = ["full"] }
-tracing = "0.1"
-tracing-subscriber = "0.3"
-anyhow = "1"
-rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
-
-wzp-proto = { path = "../../crates/wzp-proto" }
-wzp-codec = { path = "../../crates/wzp-codec" }
-wzp-fec = { path = "../../crates/wzp-fec" }
-wzp-crypto = { path = "../../crates/wzp-crypto" }
-wzp-transport = { path = "../../crates/wzp-transport" }
-
-[target.'cfg(not(target_os = "android"))'.dependencies]
-wzp-client = { path = "../../crates/wzp-client", features = ["audio", "vpio"] }
-
-[target.'cfg(target_os = "android")'.dependencies]
-wzp-client = { path = "../../crates/wzp-client", default-features = false }
-```
-
----
-
-## Reproduction
-
-A fresh clone on a Linux x86_64 host with:
-
-```bash
-git clone ssh://git@git.manko.yoga:222/manawenuz/wz-phone.git
-cd wz-phone
-git checkout feat/desktop-audio-rewrite
-git reset --hard 0d74366   # <-- step E.1, smallest crashing commit
-
-# Need: Android NDK r26.1.10909125, JDK 17, Node 20, Rust stable, cargo tauri 2.x
-scripts/prep-linux-mint.sh    # installs all the above into /opt/android-sdk etc.
-
-cd desktop
-npm install
-cd src-tauri
-cargo tauri android build --debug --target aarch64 --apk
-adb install -r gen/android/app/build/outputs/apk/universal/debug/app-universal-debug.apk
-adb logcat -c && adb shell am start -n com.wzp.desktop/.MainActivity
-adb logcat | grep -E "F DEBUG|__init_tcb|pthread_create"
-```
-
-Expected result: SIGSEGV at `__init_tcb+4` within ~500 ms of launch.
-
-Reverting `cpp/cpp_smoke.cpp` + the `cc::Build` call for it in `build.rs`
-(one git command: `git revert 0d74366 aa240c6 0224ce6 a852cad`) restores a
-working build. Keeping the C sanity compile (`hello.c`, `getauxval_fix.c`)
-is fine — only the `.cpp(true) + .cpp_link_stdlib("c++_shared")` combination
-triggers the regression.
-
----
-
-## What we'd like help with
-
-1. **Is our suspect #2 actually the mechanism?** Is there a known issue
-   where a Tauri/tao android cdylib crashes on load when it has a
-   `libc++_shared.so` NEEDED entry and tries to spawn a thread from inside
-   an onCreate JNI call?
-
-2. **What's the correct way to link Oboe (or any C++ Android audio
-   library) into a `cargo tauri android build` cdylib** without hitting
-   this? Is there a known-good combination of cc-rs flags / linker
-   arguments / cargo config?
-
-3. **Is there a way to force `cargo tauri` to use the same linker setup
-   as `cargo ndk`**, which reliably produces working Oboe-linked .so
-   files from the exact same workspace? We've tried env var override,
-   `.cargo/config.toml`, and image-level binary replacement — cargo
-   tauri ignores all three and keeps using
-   `aarch64-linux-android24-clang`.
-
-4. **Is there a way to defer `tao::ndk_glue::create`'s thread spawn to
-   after `onCreate` returns** so that whatever bionic state `__init_tcb`
-   depends on is ready?
-
-5. **Lastly** — is there a fundamentally different approach we should
-   take (e.g., use the `oboe` Rust crate from crates.io instead of a
-   hand-rolled C++ bridge, use Android's AAudio directly via the `ndk`
-   crate's aaudio bindings, or even abandon the C++ audio path and
-   implement mic/speaker via JNI into Java `AudioRecord`/`AudioTrack`)?

scripts/Dockerfile.linux-desktop-builder

@@ -0,0 +1,59 @@
+# =============================================================================
+# WZ Phone — Linux x86_64 Tauri desktop build image
+#
+# Thin extension of wzp-android-builder that adds the GTK3 + WebKit2GTK 4.1 +
+# libsoup-3.0 + AppIndicator dev packages needed to build the Tauri desktop
+# app for Linux. Everything else (Rust, Node.js, cmake, pkg-config, cpal
+# libasound deps, tauri-cli) is inherited from the base image.
+#
+# Build:
+#   docker build -t wzp-linux-desktop-builder -f Dockerfile.linux-desktop-builder .
+#
+# Run: driven by scripts/build-linux-desktop-docker.sh (see that file).
+# =============================================================================
+FROM wzp-android-builder
+
+USER root
+
+# Tauri 2.x Linux dependencies.
+# - libwebkit2gtk-4.1-dev: the WebView backend. Tauri 2.x uses 4.1 (not 4.0).
+# - libsoup-3.0-dev: HTTP client used by webkit2gtk. Must match its major.
+# - libgtk-3-dev: GTK3 headers (webkit2gtk still uses GTK3).
+# - libayatana-appindicator3-dev: system tray / status icon. Optional at
+#   runtime but tauri-build's feature-detection includes it.
+# - librsvg2-dev: SVG rendering in the menu/icon code.
+# - libglib2.0-dev: GObject introspection headers (transitive, but explicit).
+# - patchelf: used by the tauri bundler to rewrite rpaths in the final binary.
+# - file: already in the base, but tauri-build checks for it by name.
+RUN apt-get update && apt-get install -y --no-install-recommends \
+        libwebkit2gtk-4.1-dev \
+        libsoup-3.0-dev \
+        libgtk-3-dev \
+        libayatana-appindicator3-dev \
+        librsvg2-dev \
+        libglib2.0-dev \
+        patchelf \
+        libwebrtc-audio-processing-dev \
+        clang \
+    && rm -rf /var/lib/apt/lists/*
+
+# ── webrtc-audio-processing build requirements ──────────────────────────────
+# The `webrtc-audio-processing` Rust crate (0.3.x line) links against Debian
+# Bookworm's `libwebrtc-audio-processing-dev` apt package (0.3-1+b1), which
+# provides the PulseAudio fork of the WebRTC audio processing module. This is
+# the library that Pulse's module-echo-cancel and PipeWire's filter-chain
+# use for their AEC modes — same algorithm family, runtime-linked via
+# pkg-config at cargo build time.
+#
+# An attempt was made to use the 2.x line with the `bundled` sub-feature
+# (which would give AEC3 instead of AEC2) but both the crates.io tarball
+# and the upstream git `main` branch hit a `meson setup --reconfigure` bug
+# that panics on first-run empty build dirs. The 0.3 line avoids the
+# bundled build path entirely and is what we ship for now.
+#
+# `clang` is listed explicitly because the Rust crate's bindgen may need
+# it at compile time depending on the version of the underlying
+# webrtc-audio-processing-sys build script.
+
+USER builder
+WORKDIR /build/source

scripts/Dockerfile.windows-builder

@@ -0,0 +1,99 @@
+# =============================================================================
+# WZ Phone — Windows (x86_64-pc-windows-msvc) cross-compile image
+#
+# Cross-compiles the Tauri desktop binary for Windows from a Linux host via
+# `cargo xwin`, which auto-downloads the Microsoft CRT + Windows SDK at build
+# time. This image pre-warms that cache so the cross-compile is as close as
+# possible to a native Linux build on rebuild (~3 min warm vs ~20 min cold).
+#
+# Build:
+#   docker build -t wzp-windows-builder -f Dockerfile.windows-builder .
+#
+# Run: driven by scripts/build-windows-docker.sh (see that file).
+# =============================================================================
+FROM debian:bookworm
+
+ARG RUST_TARGET=x86_64-pc-windows-msvc
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+# ── System packages ──────────────────────────────────────────────────────────
+# - build-essential + pkg-config + libssl-dev: baseline cargo build toolchain
+# - cmake + ninja-build: audiopus_sys (libopus) uses cmake and expects Ninja
+#   as the generator for the windows target; without ninja-build the cmake
+#   build fails with "CMake was unable to find a build program corresponding
+#   to Ninja" partway through.
+# - llvm + clang + lld: cargo-xwin uses clang + lld-link for PE/COFF output.
+# - nasm: ring / rustls assembly for Windows needs NASM on non-Windows hosts.
+# - curl, git, ca-certificates, unzip: obvious plumbing.
+# - xz-utils: some Microsoft installer archives are xz-compressed.
+RUN apt-get update && apt-get install -y --no-install-recommends \
+        build-essential \
+        cmake \
+        ninja-build \
+        curl \
+        git \
+        pkg-config \
+        libssl-dev \
+        ca-certificates \
+        llvm \
+        clang \
+        lld \
+        nasm \
+        unzip \
+        xz-utils \
+        file \
+    && rm -rf /var/lib/apt/lists/*
+
+# ── Node.js 20 LTS (required by Tauri for frontend build) ────────────────────
+RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - \
+    && apt-get install -y --no-install-recommends nodejs \
+    && rm -rf /var/lib/apt/lists/* \
+    && node --version \
+    && npm --version
+
+# ── Builder user (1000:1000) — matches host bind-mount UID for the cache
+#    volumes so cargo-registry / target survive across runs without perms
+#    gymnastics.
+RUN groupadd -g 1000 builder \
+    && useradd -m -u 1000 -g 1000 -s /bin/bash builder
+
+USER builder
+WORKDIR /home/builder
+
+# ── Rust toolchain + Windows target + cargo-xwin ────────────────────────────
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
+        | sh -s -- -y --default-toolchain stable \
+    && . $HOME/.cargo/env \
+    && rustup target add ${RUST_TARGET} \
+    && cargo install cargo-xwin --locked
+
+ENV PATH="/home/builder/.cargo/bin:$PATH" \
+    XWIN_ACCEPT_LICENSE=1 \
+    RUST_TARGET_WIN=${RUST_TARGET}
+
+# ── Pre-warm the xwin cache ─────────────────────────────────────────────────
+# cargo-xwin downloads the Microsoft CRT + Windows SDK (~1.5-2 GB) into
+# ~/.cache/cargo-xwin the first time it runs. Baking that into an image
+# layer saves ~4 minutes off every subsequent cold run.
+#
+# We do this by creating a throwaway Rust project, building it with
+# cargo-xwin against the Windows target, then deleting the project but
+# keeping the xwin cache.
+RUN set -eux; \
+    mkdir -p /tmp/xwin-warmup && cd /tmp/xwin-warmup && \
+    . $HOME/.cargo/env && \
+    cargo new --bin xwin-warmup --quiet && \
+    cd xwin-warmup && \
+    cargo xwin build --release --target ${RUST_TARGET} 2>&1 | tail -5 && \
+    cd / && rm -rf /tmp/xwin-warmup && \
+    du -sh $HOME/.cache/cargo-xwin
+
+# Note: the libopus SSE4.1/SSSE3 intrinsic compile failure under clang-cl
+# is fixed at the source level by vendoring audiopus_sys and patching its
+# bundled libopus CMakeLists.txt (see desktop/vendor/audiopus_sys in the
+# source tree). Do NOT try to patch cargo-xwin's override.cmake at this
+# layer — cargo-xwin rewrites that file on every `cargo xwin build`
+# invocation, so any edits baked into the image are wiped at runtime.
+
+WORKDIR /build/source

scripts/build-and-notify.sh

@@ -139,7 +139,7 @@ ls -lh android/app/src/main/jniLibs/arm64-v8a/
 
 echo ">>> APK build..."
 cd android && chmod +x gradlew
-./gradlew clean assembleDebug --no-daemon --warning-mode=none 2>&1 | tail -50
+./gradlew clean assembleDebug --no-daemon --warning-mode=none 2>&1 | tail -3
 echo "APK_BUILT"
 '
 
@@ -153,7 +153,7 @@ if [ -n "$APK" ]; then
     notify "WZP Android [$BRANCH @ $GIT_HASH] done! APK: $URL"
     echo ">>> Done! APK at: $URL"
 else
-    notify "WZP build FAILED [$BRANCH @ $GIT_HASH] - no APK"
+    notify "WZP Android FAILED [$BRANCH @ $GIT_HASH] - no APK"
     echo "ERROR: No APK found"
     exit 1
 fi

scripts/build-linux-desktop-docker.sh

@@ -0,0 +1,312 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# =============================================================================
+# WZ Phone — Linux x86_64 Tauri desktop build (Docker on SepehrHomeserverdk)
+#
+# Cross-compiles the Tauri desktop binary for Linux x86_64 inside the
+# wzp-linux-desktop-builder image (a thin extension of wzp-android-builder
+# that adds GTK3 + WebKit2GTK 4.1 + libsoup-3.0 + appindicator dev packages).
+#
+# Fires an ntfy.sh/wzp notification on build start and build completion, and
+# uploads the resulting .deb + raw binary to rustypaste.
+#
+# Usage:
+#   ./scripts/build-linux-desktop-docker.sh                # Full pipeline
+#   ./scripts/build-linux-desktop-docker.sh --no-pull      # Skip git fetch
+#   ./scripts/build-linux-desktop-docker.sh --rust         # Clean Rust target
+#   ./scripts/build-linux-desktop-docker.sh --image-build  # (Re)build image
+#
+# Environment:
+#   WZP_BRANCH   Branch to build (default: feat/desktop-audio-rewrite)
+# =============================================================================
+
+REMOTE_HOST="SepehrHomeserverdk"
+BASE_DIR="/mnt/storage/manBuilder"
+NTFY_TOPIC="https://ntfy.sh/wzp"
+LOCAL_OUTPUT="target/linux-desktop"
+BRANCH="${WZP_BRANCH:-feat/desktop-audio-rewrite}"
+SSH_OPTS="-o ConnectTimeout=15 -o ServerAliveInterval=15 -o ServerAliveCountMax=4 -o LogLevel=ERROR"
+
+REBUILD_RUST=0
+DO_PULL=1
+IMAGE_BUILD=0
+# WITH_AEC=1 enables the wzp-client `linux-aec` feature (WebRTC AEC via
+# webrtc-audio-processing) and renames the output artifacts with an `-aec`
+# suffix so both variants can coexist on disk.
+WITH_AEC=0
+for arg in "$@"; do
+    case "$arg" in
+        --rust)         REBUILD_RUST=1 ;;
+        --pull)         DO_PULL=1 ;;
+        --no-pull)      DO_PULL=0 ;;
+        --image-build)  IMAGE_BUILD=1 ;;
+        --aec)          WITH_AEC=1 ;;
+        -h|--help)
+            sed -n '3,25p' "$0"
+            exit 0
+            ;;
+    esac
+done
+
+# Variant suffix used locally to rename downloaded artifacts so the noAEC
+# baseline and the AEC build can coexist in $LOCAL_OUTPUT. Mirrors the
+# same VARIANT declaration inside the remote REMOTE_SCRIPT heredoc.
+if [ "$WITH_AEC" = "1" ]; then
+    VARIANT="aec"
+else
+    VARIANT="noAEC"
+fi
+
+log() { echo -e "\033[1;36m>>> $*\033[0m"; }
+ssh_cmd() { ssh $SSH_OPTS "$REMOTE_HOST" "$@"; }
+
+notify_local() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
+
+mkdir -p "$LOCAL_OUTPUT"
+
+# ─── Optional: (re)build the docker image on the remote ────────────────────
+if [ "$IMAGE_BUILD" = "1" ]; then
+    log "Uploading Dockerfile.linux-desktop-builder to remote..."
+    scp $SSH_OPTS "$(dirname "$0")/Dockerfile.linux-desktop-builder" \
+        "$REMOTE_HOST:$BASE_DIR/Dockerfile.linux-desktop-builder"
+
+    log "Triggering remote image build (fire-and-forget)..."
+    ssh_cmd "cd $BASE_DIR && \
+        nohup docker build -f Dockerfile.linux-desktop-builder \
+            -t wzp-linux-desktop-builder . \
+            > /tmp/wzp-linux-desktop-image-build.log 2>&1 & \
+        echo 'image build PID: '\$!"
+    notify_local "WZP Linux desktop image build dispatched"
+    log "Image build running in background on $REMOTE_HOST."
+    log "Tail the log with:  ssh $REMOTE_HOST 'tail -f /tmp/wzp-linux-desktop-image-build.log'"
+    exit 0
+fi
+
+# ─── Upload remote build runner script ─────────────────────────────────────
+log "Uploading remote build script..."
+ssh_cmd "cat > /tmp/wzp-linux-desktop-build.sh" <<'REMOTE_SCRIPT'
+#!/usr/bin/env bash
+set -euo pipefail
+
+BASE_DIR="/mnt/storage/manBuilder"
+NTFY_TOPIC="https://ntfy.sh/wzp"
+BRANCH="${1:-feat/desktop-audio-rewrite}"
+DO_PULL="${2:-1}"
+REBUILD_RUST="${3:-0}"
+WITH_AEC="${4:-0}"
+
+LOG_FILE=/tmp/wzp-linux-desktop-build.log
+GIT_HASH="unknown"
+ENV_FILE="$BASE_DIR/.env"
+
+# Variant suffix for artifact filenames so the noAEC baseline and the AEC
+# build can coexist on the host. Applied after the build to the downloaded
+# files (we can't easily rename during the cargo tauri build itself).
+if [ "$WITH_AEC" = "1" ]; then
+    VARIANT="aec"
+else
+    VARIANT="noAEC"
+fi
+
+notify() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
+
+# Upload to rustypaste; print URL on stdout (or empty on failure).
+upload_to_rustypaste() {
+    local file="$1"
+    [ ! -f "$file" ] && { echo ""; return; }
+    # shellcheck disable=SC1090
+    source "$ENV_FILE"
+    if [ -n "${rusty_address:-}" ] && [ -n "${rusty_auth_token:-}" ]; then
+        curl -s -F "file=@$file" -H "Authorization: $rusty_auth_token" "$rusty_address" || echo ""
+    else
+        echo ""
+    fi
+}
+
+on_error() {
+    local line="$1"
+    local log_url
+    log_url=$(upload_to_rustypaste "$LOG_FILE" || echo "")
+    if [ -n "$log_url" ]; then
+        notify "WZP Linux desktop build FAILED [$GIT_HASH] (line $line)
+log: $log_url"
+    else
+        notify "WZP Linux desktop build FAILED [$GIT_HASH] (line $line) — log upload failed"
+    fi
+}
+trap 'on_error $LINENO' ERR
+
+exec > >(tee "$LOG_FILE") 2>&1
+
+# ── git fetch + reset the target branch ───────────────────────────────────
+if [ "$DO_PULL" = "1" ]; then
+    echo ">>> git fetch + reset $BRANCH"
+    cd "$BASE_DIR/data/source"
+    git reset --hard HEAD 2>/dev/null || true
+    git gc --prune=now 2>/dev/null || true
+    git fetch origin "$BRANCH" 2>&1 | tail -3
+    git checkout "$BRANCH" 2>/dev/null || git checkout -b "$BRANCH" "origin/$BRANCH"
+    git reset --hard "origin/$BRANCH"
+    git submodule update --init --recursive || true
+fi
+
+GIT_HASH=$(cd "$BASE_DIR/data/source" && git rev-parse --short HEAD 2>/dev/null || echo unknown)
+GIT_MSG=$(cd "$BASE_DIR/data/source" && git log -1 --pretty=%s 2>/dev/null | head -c 60 || echo "?")
+notify "WZP Linux desktop build STARTED [$GIT_HASH] — $GIT_MSG"
+
+# Fix perms so builder uid 1000 can read/write the mounted source.
+find "$BASE_DIR/data/source" "$BASE_DIR/data/cache-linux-desktop" \
+    ! -user 1000 -o ! -group 1000 2>/dev/null | \
+    xargs -r chown 1000:1000 2>/dev/null || true
+
+if [ "$REBUILD_RUST" = "1" ]; then
+    echo ">>> Cleaning Linux desktop Rust target dir..."
+    rm -rf "$BASE_DIR/data/cache-linux-desktop/target/x86_64-unknown-linux-gnu" \
+           "$BASE_DIR/data/cache-linux-desktop/target/release"
+fi
+
+# ── Docker run ─────────────────────────────────────────────────────────────
+# Cache volumes:
+#   - cargo-registry / cargo-git: shared with the android builder — both use
+#     the same crates, so the download cache is worth sharing.
+#   - cache-linux-desktop/target: separate target tree for the desktop build
+#     to keep it isolated from the Linux CLI build (build-linux-docker.sh
+#     uses cache-linux/target for wzp-relay / wzp-client).
+
+mkdir -p "$BASE_DIR/data/cache/cargo-registry" \
+         "$BASE_DIR/data/cache/cargo-git" \
+         "$BASE_DIR/data/cache-linux-desktop/target"
+chown -R 1000:1000 "$BASE_DIR/data/cache-linux-desktop/target" 2>/dev/null || true
+
+# Pass WITH_AEC into the docker container so the inner build script can
+# decide whether to enable the wzp-client `linux-aec` feature.
+docker run --rm \
+    --user 1000:1000 \
+    -e WITH_AEC="$WITH_AEC" \
+    -v "$BASE_DIR/data/source:/build/source" \
+    -v "$BASE_DIR/data/cache/cargo-registry:/home/builder/.cargo/registry" \
+    -v "$BASE_DIR/data/cache/cargo-git:/home/builder/.cargo/git" \
+    -v "$BASE_DIR/data/cache-linux-desktop/target:/build/source/target" \
+    wzp-linux-desktop-builder \
+    bash -c '
+set -euo pipefail
+
+cd /build/source/desktop
+
+echo ">>> npm install"
+npm install --silent 2>&1 | tail -5 || npm install 2>&1 | tail -20
+
+echo ">>> npm run build"
+npm run build 2>&1 | tail -5
+
+# The linux-aec feature enables a WebRTC AEC3 capture backend in
+# wzp-client. Opt in only when the caller asked for it; noAEC baseline
+# builds keep the plain CPAL path for comparison. Tauri does not
+# propagate --features through to the wzp-desktop crate directly
+# because `cargo tauri build` invokes cargo underneath — so we use
+# `cargo tauri build -- --features wzp-desktop/linux-aec` to pass it
+# through. Wait — wzp-desktop is the bin crate, and its `linux-aec`
+# feature needs to be defined there too. The simpler path is to set
+# the feature at the wzp-client level via a bin-crate feature that
+# forwards to wzp-client. Handled in Cargo.toml changes.
+if [ "${WITH_AEC:-0}" = "1" ]; then
+    echo ">>> cargo tauri build WITH linux-aec feature"
+    cd src-tauri
+    cargo tauri build -- --features wzp-desktop/linux-aec 2>&1 | tail -40
+else
+    echo ">>> cargo tauri build (noAEC baseline)"
+    cd src-tauri
+    cargo tauri build 2>&1 | tail -40
+fi
+
+echo ""
+echo ">>> Build artifacts:"
+ls -lh /build/source/target/release/wzp-desktop 2>/dev/null || echo "NO BINARY"
+ls -lh /build/source/target/release/bundle/deb/*.deb 2>/dev/null || echo "NO DEB"
+ls -lh /build/source/target/release/bundle/appimage/*.AppImage 2>/dev/null || echo "NO APPIMAGE"
+'
+
+# Locate the produced artifacts
+BIN="$BASE_DIR/data/cache-linux-desktop/target/release/wzp-desktop"
+DEB=$(ls "$BASE_DIR/data/cache-linux-desktop/target/release/bundle/deb/"*.deb 2>/dev/null | head -1 || true)
+APPIMAGE=$(ls "$BASE_DIR/data/cache-linux-desktop/target/release/bundle/appimage/"*.AppImage 2>/dev/null | head -1 || true)
+
+if [ ! -f "$BIN" ]; then
+    LOG_URL=$(upload_to_rustypaste "$LOG_FILE" || echo "")
+    if [ -n "$LOG_URL" ]; then
+        notify "WZP Linux desktop build [$GIT_HASH]: no binary produced
+log: $LOG_URL"
+    else
+        notify "WZP Linux desktop build [$GIT_HASH]: no binary produced — log upload failed"
+    fi
+    exit 1
+fi
+
+BIN_SIZE=$(du -h "$BIN" | cut -f1)
+
+# Prefer to ship the .deb if we got one, otherwise fall back to the raw binary.
+ARTIFACT="$BIN"
+ARTIFACT_KIND="binary"
+if [ -n "$DEB" ] && [ -f "$DEB" ]; then
+    ARTIFACT="$DEB"
+    ARTIFACT_KIND="deb"
+    ARTIFACT_SIZE=$(du -h "$DEB" | cut -f1)
+else
+    ARTIFACT_SIZE="$BIN_SIZE"
+fi
+
+RUSTY_URL=$(upload_to_rustypaste "$ARTIFACT" || echo "")
+if [ -n "$RUSTY_URL" ]; then
+    notify "WZP Linux desktop build OK [$GIT_HASH] ($ARTIFACT_KIND, $ARTIFACT_SIZE)
+$RUSTY_URL"
+else
+    notify "WZP Linux desktop build OK [$GIT_HASH] ($ARTIFACT_KIND, $ARTIFACT_SIZE) — rustypaste upload skipped"
+fi
+
+# Print paths so the local script can scp them back
+echo "BIN_REMOTE_PATH=$BIN"
+[ -n "$DEB" ] && echo "DEB_REMOTE_PATH=$DEB"
+[ -n "$APPIMAGE" ] && echo "APPIMAGE_REMOTE_PATH=$APPIMAGE"
+REMOTE_SCRIPT
+
+ssh_cmd "chmod +x /tmp/wzp-linux-desktop-build.sh"
+
+notify_local "WZP Linux desktop build dispatched (branch=$BRANCH)"
+log "Triggering remote build (branch=$BRANCH)..."
+
+# Run; last lines are *_REMOTE_PATH=...
+REMOTE_OUTPUT=$(ssh_cmd "/tmp/wzp-linux-desktop-build.sh '$BRANCH' '$DO_PULL' '$REBUILD_RUST' '$WITH_AEC'" || true)
+echo "$REMOTE_OUTPUT" | tail -80
+
+BIN_REMOTE=$(echo "$REMOTE_OUTPUT" | grep '^BIN_REMOTE_PATH=' | tail -1 | cut -d= -f2-)
+DEB_REMOTE=$(echo "$REMOTE_OUTPUT" | grep '^DEB_REMOTE_PATH=' | tail -1 | cut -d= -f2-)
+APPIMAGE_REMOTE=$(echo "$REMOTE_OUTPUT" | grep '^APPIMAGE_REMOTE_PATH=' | tail -1 | cut -d= -f2-)
+
+if [ -n "$BIN_REMOTE" ]; then
+    log "Downloading wzp-desktop binary to $LOCAL_OUTPUT/wzp-desktop-$VARIANT ..."
+    scp $SSH_OPTS "$REMOTE_HOST:$BIN_REMOTE" "$LOCAL_OUTPUT/wzp-desktop-$VARIANT"
+    echo "  $LOCAL_OUTPUT/wzp-desktop-$VARIANT ($(du -h "$LOCAL_OUTPUT/wzp-desktop-$VARIANT" | cut -f1))"
+fi
+
+if [ -n "$DEB_REMOTE" ]; then
+    # Apply the variant suffix to the downloaded .deb: cargo-tauri names the
+    # file WarzonePhone_<version>_amd64.deb regardless of what we built, so
+    # the variant lives only in our chosen filename.
+    DEB_BASENAME=$(basename "$DEB_REMOTE" .deb)
+    log "Downloading .deb to $LOCAL_OUTPUT/${DEB_BASENAME}-$VARIANT.deb ..."
+    scp $SSH_OPTS "$REMOTE_HOST:$DEB_REMOTE" "$LOCAL_OUTPUT/${DEB_BASENAME}-$VARIANT.deb"
+    ls -lh "$LOCAL_OUTPUT/${DEB_BASENAME}-$VARIANT.deb"
+fi
+
+if [ -n "$APPIMAGE_REMOTE" ]; then
+    APPIMG_BASENAME=$(basename "$APPIMAGE_REMOTE" .AppImage)
+    log "Downloading .AppImage to $LOCAL_OUTPUT/${APPIMG_BASENAME}-$VARIANT.AppImage ..."
+    scp $SSH_OPTS "$REMOTE_HOST:$APPIMAGE_REMOTE" "$LOCAL_OUTPUT/${APPIMG_BASENAME}-$VARIANT.AppImage"
+    ls -lh "$LOCAL_OUTPUT/${APPIMG_BASENAME}-$VARIANT.AppImage"
+fi
+
+if [ -z "$BIN_REMOTE" ]; then
+    log "No binary produced — see ntfy / remote log /tmp/wzp-linux-desktop-build.log"
+    exit 1
+fi

scripts/build-linux-docker.sh

@@ -17,6 +17,12 @@ NTFY_TOPIC="https://ntfy.sh/wzp"
 LOCAL_OUTPUT="target/linux-x86_64"
 SSH_OPTS="-o ConnectTimeout=15 -o ServerAliveInterval=15 -o ServerAliveCountMax=4 -o LogLevel=ERROR"
 
+# Branch to build. Default matches the current active development branch
+# (opus-DRED-v2 as of 2026-04-11). Override with `WZP_BRANCH=<name> ./build-linux-docker.sh`
+# if you need a different one — e.g. to rebuild the relay from a feature
+# branch for A/B testing.
+WZP_BRANCH="${WZP_BRANCH:-opus-DRED-v2}"
+
 DO_PULL=1
 DO_CLEAN=0
 DO_INSTALL=0
@@ -44,19 +50,21 @@ BASE_DIR="/mnt/storage/manBuilder"
 NTFY_TOPIC="https://ntfy.sh/wzp"
 DO_PULL="${1:-0}"
 DO_CLEAN="${2:-0}"
+BRANCH="${3:-opus-DRED-v2}"
 
 notify() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
 
 trap 'notify "WZP Linux build FAILED! Check /tmp/wzp-linux-build.log"' ERR
 
 if [ "$DO_PULL" = "1" ]; then
-    echo ">>> Pulling latest..."
+    echo ">>> Pulling latest ($BRANCH)..."
     cd "$BASE_DIR/data/source"
     git reset --hard HEAD 2>/dev/null || true
     git clean -fd 2>/dev/null || true
     git gc --prune=now 2>/dev/null || true
-    git fetch origin feat/android-voip-client 2>&1 | tail -3
+    git fetch origin "$BRANCH" 2>&1 | tail -3
-    git reset --hard origin/feat/android-voip-client 2>/dev/null || true
+    git checkout "$BRANCH" 2>/dev/null || git checkout -b "$BRANCH" "origin/$BRANCH"
+    git reset --hard "origin/$BRANCH" 2>/dev/null || true
 fi
 
 if [ "$DO_CLEAN" = "1" ]; then
@@ -133,7 +141,7 @@ ssh_cmd "chmod +x /tmp/wzp-linux-build.sh"
 # Run in tmux
 log "Starting Linux build in tmux..."
 ssh_cmd "tmux kill-session -t wzp-linux 2>/dev/null; true"
-ssh_cmd "tmux new-session -d -s wzp-linux '/tmp/wzp-linux-build.sh $DO_PULL $DO_CLEAN 2>&1 | tee /tmp/wzp-linux-build.log'"
+ssh_cmd "tmux new-session -d -s wzp-linux '/tmp/wzp-linux-build.sh $DO_PULL $DO_CLEAN $WZP_BRANCH 2>&1 | tee /tmp/wzp-linux-build.log'"
 
 log "Build running! Notification on ntfy.sh/wzp when done."
 echo ""

scripts/build-tauri-android.sh

@@ -199,6 +199,29 @@ else
     echo ">>> WARNING: libwzp_native.so not produced"
 fi
 
+# ─── libc++_shared.so — required by wzp-native at runtime ──────────────
+# wzp-native/build.rs uses cpp_link_stdlib(Some("c++_shared")) which adds
+# a NEEDED entry for libc++_shared.so to libwzp_native.so. cargo-ndk does
+# NOT copy the actual libc++_shared.so into jniLibs, so unless we copy it
+# explicitly, the APK ships without it and the Android dynamic linker
+# fails the dlopen with "library libc++_shared.so not found" at runtime.
+# Same fix that build-and-notify.sh has had for the legacy wzp-android
+# path (lines 126-134 there) — ported here for the Tauri pipeline.
+# NOTE: no apostrophes in this comment block. The enclosing docker
+# bash -c uses single quotes and a stray apostrophe closes the string
+# prematurely, breaking variable scope for everything below.
+if [ ! -f "$JNI_ABI_DIR/libc++_shared.so" ]; then
+    echo ">>> libc++_shared.so missing, copying from NDK..."
+    NDK_LIBCXX=$(find "$ANDROID_NDK_HOME" -name "libc++_shared.so" -path "*/aarch64-linux-android/*" | head -1)
+    if [ -n "$NDK_LIBCXX" ]; then
+        cp "$NDK_LIBCXX" "$JNI_ABI_DIR/"
+        ls -lh "$JNI_ABI_DIR/libc++_shared.so"
+    else
+        echo ">>> ERROR: libc++_shared.so not found in NDK — APK will crash at dlopen time"
+        exit 1
+    fi
+fi
+
 echo ">>> cargo tauri android build ${PROFILE_FLAG} --target aarch64 --apk"
 cargo tauri android build ${PROFILE_FLAG} --target aarch64 --apk
 

scripts/build-windows-cloud.sh

@@ -0,0 +1,391 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Build WarzonePhone desktop .exe for Windows x86_64 using a temporary
+# Hetzner Cloud VPS. Cross-compiles from Linux via `cargo xwin`, which
+# auto-downloads the Windows SDK + MSVC CRT the first time it runs.
+#
+# No Windows machine needed for the build itself — the produced .exe
+# still has to be copied to a real Windows host to run (we can only
+# verify compile + link here, not runtime).
+#
+# Prerequisites:
+#   - hcloud CLI authenticated
+#   - SSH key "wz" registered in Hetzner
+#   - Local ssh-agent loaded with an SSH key that can read the
+#     git.manko.yoga repo (the script forwards the agent so the VM's
+#     git clone uses your identity). Run `ssh-add /Users/manwe/CascadeProjects/wzp`
+#     once before invoking this script if you haven't already.
+#
+# Usage:
+#   ./scripts/build-windows-cloud.sh              Full build (create → build → download → destroy)
+#   ./scripts/build-windows-cloud.sh --prepare    Create VM and install deps only
+#   ./scripts/build-windows-cloud.sh --build      Build on existing VM
+#   ./scripts/build-windows-cloud.sh --transfer   Download .exe from VM
+#   ./scripts/build-windows-cloud.sh --destroy    Delete the VM
+#   ./scripts/build-windows-cloud.sh --all        prepare + build + transfer (VM persists)
+#   ./scripts/build-windows-cloud.sh --upload     Re-upload source to existing VM
+#
+# Environment variables (all optional):
+#   WZP_BRANCH       Branch to build      (default: feat/desktop-audio-rewrite)
+#   WZP_SERVER_TYPE  Hetzner server type  (default: cx23 — small, cheap, x86)
+#   WZP_KEEP_VM      Set to 1 to skip destroy on full build
+
+SSH_KEY_NAME="wz"
+SSH_KEY_PATH="/Users/manwe/CascadeProjects/wzp"
+SERVER_TYPE="${WZP_SERVER_TYPE:-cx33}"   # cx23 (4GB RAM) OOMs on tauri+rustls cross-compile — bump to cx33 (8GB, 8 vCPU)
+IMAGE="ubuntu-24.04"
+SERVER_NAME="wzp-windows-builder"
+REMOTE_USER="root"
+OUTPUT_DIR="target/windows-exe"
+PROJECT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+BRANCH="${WZP_BRANCH:-feat/desktop-audio-rewrite}"
+KEEP_VM="${WZP_KEEP_VM:-0}"
+
+SSH_OPTS="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o ConnectTimeout=10 -o LogLevel=ERROR"
+
+RUST_TARGET="x86_64-pc-windows-msvc"
+
+NTFY_TOPIC="https://ntfy.sh/wzp"
+RUSTY_ENV_FILE="$HOME/.wzp/rustypaste.env"
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+log()  { echo -e "\n\033[1;36m>>> $*\033[0m"; }
+err()  { echo -e "\033[1;31mERROR: $*\033[0m" >&2; }
+die()  {
+  err "$@"
+  notify "WZP Windows build FAILED — $*"
+  # If the user wants to keep the VM alive for debugging (WZP_KEEP_VM=1),
+  # don't tear it down on failure — they might want to ssh in and poke at
+  # the build state. Only auto-destroy when KEEP_VM is explicitly off.
+  if [ "${KEEP_VM:-0}" != "1" ]; then
+    do_destroy_quiet
+  else
+    err "VM kept alive for debugging (WZP_KEEP_VM=1). Destroy with $0 --destroy"
+  fi
+  exit 1
+}
+
+notify() {
+  # Fire-and-forget ntfy. Silently ignored if there's no network.
+  curl -sf -m 5 -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true
+}
+
+# Upload a file to the online rustypaste (paste.dk.manko.yoga), return
+# the public URL on stdout. Requires $RUSTY_ENV_FILE to contain
+# rusty_address + rusty_auth_token (synced from SepehrHomeserverdk's
+# /mnt/storage/manBuilder/.env once; see README).
+rustypaste_upload() {
+  local file="$1"
+  [ -f "$file" ] || { echo ""; return; }
+  [ -f "$RUSTY_ENV_FILE" ] || { echo ""; return; }
+  # shellcheck disable=SC1090
+  source "$RUSTY_ENV_FILE"
+  if [ -n "${rusty_address:-}" ] && [ -n "${rusty_auth_token:-}" ]; then
+    curl -s -F "file=@$file" -H "Authorization: $rusty_auth_token" "$rusty_address" || echo ""
+  else
+    echo ""
+  fi
+}
+
+get_vm_ip() {
+  hcloud server list -o columns=name,ipv4 -o noheader 2>/dev/null | grep "$SERVER_NAME" | awk '{print $2}' | tr -d ' '
+}
+
+ssh_cmd() {
+  local ip
+  ip=$(get_vm_ip)
+  [ -n "$ip" ] || die "No VM found. Run --prepare first."
+  ssh $SSH_OPTS -A -i "$SSH_KEY_PATH" "$REMOTE_USER@$ip" "$@"
+}
+
+scp_down() {
+  local ip
+  ip=$(get_vm_ip)
+  [ -n "$ip" ] || die "No VM found."
+  scp $SSH_OPTS -i "$SSH_KEY_PATH" "$REMOTE_USER@$ip:$1" "$2"
+}
+
+do_destroy_quiet() {
+  local name
+  name=$(hcloud server list -o columns=name -o noheader 2>/dev/null | grep "$SERVER_NAME" | tr -d ' ' || true)
+  if [ -n "$name" ]; then
+    echo ""
+    err "Cleaning up — destroying VM $name"
+    hcloud server delete "$name" 2>/dev/null || true
+  fi
+}
+
+# ---------------------------------------------------------------------------
+# --prepare: Create VM, install all build dependencies
+# ---------------------------------------------------------------------------
+
+do_prepare() {
+  local existing
+  existing=$(hcloud server list -o columns=name -o noheader 2>/dev/null | grep "$SERVER_NAME" | tr -d ' ' || true)
+  if [ -n "$existing" ]; then
+    log "VM already exists: $existing — reusing"
+    do_upload
+    return
+  fi
+
+  notify "WZP Windows build STARTED ($BRANCH) — spinning up $SERVER_TYPE"
+  log "Creating Hetzner VM ($SERVER_TYPE, $IMAGE)..."
+  hcloud server create \
+    --name "$SERVER_NAME" \
+    --type "$SERVER_TYPE" \
+    --image "$IMAGE" \
+    --ssh-key "$SSH_KEY_NAME" \
+    --location fsn1 \
+    --quiet \
+    || die "Failed to create VM"
+
+  local ip
+  ip=$(get_vm_ip)
+  [ -n "$ip" ] || die "VM created but no IP found"
+  echo "  VM: $SERVER_NAME @ $ip"
+
+  log "Waiting for SSH..."
+  local ok=0
+  for i in $(seq 1 30); do
+    if ssh $SSH_OPTS -i "$SSH_KEY_PATH" "$REMOTE_USER@$ip" "echo ok" &>/dev/null; then
+      ok=1
+      break
+    fi
+    sleep 2
+  done
+  [ "$ok" -eq 1 ] || die "SSH timeout after 60s"
+
+  # System packages — cargo-xwin needs llvm/lld; ring needs nasm on
+  # Windows; audiopus_sys (libopus) uses cmake + ninja to build for the
+  # Windows target; tauri's build.rs needs the frontend dist which needs
+  # node+npm.
+  log "Installing system packages (llvm, lld, clang, nasm, ninja, node)..."
+  ssh_cmd "export DEBIAN_FRONTEND=noninteractive && \
+    apt-get update -qq && \
+    apt-get install -y -qq \
+      build-essential cmake ninja-build curl git pkg-config \
+      llvm clang lld nasm \
+      libssl-dev ca-certificates \
+      unzip wget \
+      > /dev/null 2>&1" \
+    || die "Failed to install system packages"
+
+  # Node.js 20 via NodeSource
+  ssh_cmd "curl -fsSL https://deb.nodesource.com/setup_20.x | bash - > /dev/null 2>&1 && \
+    apt-get install -y -qq nodejs > /dev/null 2>&1" \
+    || die "Failed to install Node.js"
+
+  echo "  clang: $(ssh_cmd "clang --version | head -1")"
+  echo "  node:  $(ssh_cmd "node --version")"
+  echo "  npm:   $(ssh_cmd "npm --version")"
+
+  # Rust
+  log "Installing Rust toolchain + target $RUST_TARGET..."
+  ssh_cmd "curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain stable > /dev/null 2>&1" \
+    || die "Failed to install Rust"
+  ssh_cmd "source \$HOME/.cargo/env && rustup target add $RUST_TARGET > /dev/null 2>&1" \
+    || die "Failed to add Windows target"
+  echo "  rust:  $(ssh_cmd "source \$HOME/.cargo/env && rustc --version")"
+
+  # cargo-xwin — the cross compiler glue that fetches Windows SDK + CRT
+  # on demand and shims cc/lld to produce PE/COFF output. The Microsoft
+  # license is auto-accepted via XWIN_ACCEPT_LICENSE=1 below (current
+  # cargo-xwin removed the --accept-license CLI flag in favour of the
+  # env var; --dry-run just prints what it would do).
+  log "Installing cargo-xwin..."
+  ssh_cmd "source \$HOME/.cargo/env && cargo install cargo-xwin > /dev/null 2>&1" \
+    || die "Failed to install cargo-xwin"
+  echo "  cargo-xwin: $(ssh_cmd "source \$HOME/.cargo/env && cargo xwin --version 2>&1 | head -1")"
+
+  # Make the license-accept env var persist across later ssh_cmd calls so
+  # `cargo xwin build` in do_build() doesn't prompt interactively.
+  ssh_cmd "echo 'export XWIN_ACCEPT_LICENSE=1' >> \$HOME/.bashrc"
+
+  # Do the source upload + git clone (agent-forwarded) here.
+  do_upload
+
+  log "VM ready!"
+  echo "  IP:  $ip"
+  echo "  SSH: ssh -A -i $SSH_KEY_PATH root@$ip"
+}
+
+# ---------------------------------------------------------------------------
+# --upload: Clone the repo on the VM (not rsync — the branch we want
+# lives in a separate worktree, and cloning from git is simpler + reuses
+# whatever SSH identity the calling shell has loaded in its agent).
+# ---------------------------------------------------------------------------
+
+GIT_REPO="ssh://git@git.manko.yoga:222/manawenuz/wz-phone.git"
+
+do_upload() {
+  log "Cloning wz-phone on VM (branch $BRANCH, agent-forwarded)..."
+  local ip
+  ip=$(get_vm_ip)
+  [ -n "$ip" ] || die "No VM found."
+
+  # Accept the git host key once so `git clone` doesn't hang asking.
+  ssh_cmd "mkdir -p \$HOME/.ssh && \
+    ssh-keyscan -p 222 -t rsa,ecdsa,ed25519 git.manko.yoga >> \$HOME/.ssh/known_hosts 2>/dev/null"
+
+  # Fresh clone each run — cheap on a short-lived builder VM, avoids
+  # stale state if the branch was force-pushed. --recurse-submodules so
+  # deps/featherchat (which has the warzone-protocol workspace member)
+  # comes along for the ride.
+  ssh_cmd "rm -rf /root/wzp-build && \
+    git clone --depth 1 --branch $BRANCH --recurse-submodules --shallow-submodules $GIT_REPO /root/wzp-build 2>&1 | tail -5" \
+    || die "git clone failed — is your ssh-agent loaded with a key that can read git.manko.yoga?"
+
+  echo "  Cloned $BRANCH into /root/wzp-build (with submodules)"
+}
+
+# ---------------------------------------------------------------------------
+# --build: Build frontend + cross-compile wzp-desktop.exe
+# ---------------------------------------------------------------------------
+
+do_build() {
+  log "Building frontend (vite)..."
+  ssh_cmd "cd /root/wzp-build/desktop && \
+    npm install --silent 2>&1 | tail -3 && \
+    npm run build 2>&1 | tail -5" \
+    || die "Frontend build failed"
+
+  log "Cross-compiling wzp-desktop.exe ($RUST_TARGET) via cargo-xwin..."
+  # XWIN_ACCEPT_LICENSE=1 is required by recent cargo-xwin for headless
+  # runs; --cross-compiler clang-cl picks the system clang shipped by the
+  # apt install step in do_prepare.
+  ssh_cmd "source \$HOME/.cargo/env && \
+    export XWIN_ACCEPT_LICENSE=1 && \
+    cd /root/wzp-build/desktop/src-tauri && \
+    cargo xwin build --release --target $RUST_TARGET --bin wzp-desktop 2>&1 | tail -30" \
+    || die "Windows cross-compile failed"
+
+  ssh_cmd "[ -f /root/wzp-build/target/$RUST_TARGET/release/wzp-desktop.exe ]" \
+    || die "wzp-desktop.exe not found after build"
+
+  local exe_size
+  exe_size=$(ssh_cmd "du -h /root/wzp-build/target/$RUST_TARGET/release/wzp-desktop.exe | cut -f1")
+  echo "  .exe: $exe_size"
+
+  local git_hash
+  git_hash=$(ssh_cmd "cd /root/wzp-build && git rev-parse --short HEAD")
+  notify "WZP Windows build OK [$git_hash] ($exe_size)"
+  export WZP_BUILD_GIT_HASH="$git_hash"
+  export WZP_BUILD_SIZE="$exe_size"
+}
+
+# ---------------------------------------------------------------------------
+# --transfer: Download the .exe to local machine
+# ---------------------------------------------------------------------------
+
+do_transfer() {
+  log "Downloading wzp-desktop.exe..."
+  mkdir -p "$OUTPUT_DIR"
+
+  scp_down "/root/wzp-build/target/$RUST_TARGET/release/wzp-desktop.exe" "$OUTPUT_DIR/wzp-desktop.exe"
+  local local_size
+  local_size=$(du -h "$OUTPUT_DIR/wzp-desktop.exe" | cut -f1)
+  echo "  $OUTPUT_DIR/wzp-desktop.exe ($local_size)"
+
+  # Upload to online rustypaste and notify with the URL.
+  log "Uploading to rustypaste..."
+  local url
+  url=$(rustypaste_upload "$OUTPUT_DIR/wzp-desktop.exe" || echo "")
+  if [ -n "$url" ]; then
+    echo "  $url"
+    local hash="${WZP_BUILD_GIT_HASH:-?}"
+    notify "WZP Windows build ready [$hash] ($local_size)
+$url"
+  else
+    echo "  (rustypaste upload skipped — no creds in $RUSTY_ENV_FILE)"
+    notify "WZP Windows build transferred ($local_size) — rustypaste upload skipped"
+  fi
+
+  log "Transfer complete!"
+  echo ""
+  echo "  Copy to a real Windows x86_64 host and double-click to run."
+  echo "  WebView2 runtime is required on Windows 10 (ships with Win 11)."
+}
+
+# ---------------------------------------------------------------------------
+# --destroy: Delete the VM
+# ---------------------------------------------------------------------------
+
+do_destroy() {
+  local name
+  name=$(hcloud server list -o columns=name -o noheader 2>/dev/null | grep "$SERVER_NAME" | tr -d ' ' || true)
+  if [ -z "$name" ]; then
+    echo "No VM to destroy."
+    return
+  fi
+  log "Deleting VM: $name"
+  hcloud server delete "$name"
+  echo "  Done."
+}
+
+# ---------------------------------------------------------------------------
+# Full build: create → build → transfer → destroy
+# ---------------------------------------------------------------------------
+
+do_full() {
+  trap 'err "Build failed!"; [ "${KEEP_VM:-0}" = "1" ] || do_destroy_quiet; exit 1' ERR
+
+  do_prepare
+  do_build
+  do_transfer
+
+  if [ "$KEEP_VM" = "1" ]; then
+    log "VM kept alive (WZP_KEEP_VM=1). Destroy with: $0 --destroy"
+  else
+    do_destroy
+  fi
+
+  log "All done!"
+  echo ""
+  echo "  ┌────────────────────────────────────────────────┐"
+  echo "  │ Windows .exe: $OUTPUT_DIR/wzp-desktop.exe"
+  echo "  │"
+  echo "  │ Transfer to a Windows x86_64 machine and run."
+  echo "  └────────────────────────────────────────────────┘"
+}
+
+# ---------------------------------------------------------------------------
+# Main
+# ---------------------------------------------------------------------------
+
+case "${1:-}" in
+  --prepare)  do_prepare ;;
+  --build)    do_build ;;
+  --transfer) do_transfer ;;
+  --destroy)  do_destroy ;;
+  --upload)   do_upload ;;
+  --all)
+    do_prepare
+    do_build
+    do_transfer
+    log "VM still running. Destroy with: $0 --destroy"
+    ;;
+  "")
+    do_full
+    ;;
+  *)
+    echo "Usage: $0 [--prepare|--build|--transfer|--destroy|--all|--upload]"
+    echo ""
+    echo "  (no args)    Full build: create VM → build → download → destroy VM"
+    echo "  --prepare    Create VM and install deps"
+    echo "  --build      Build on existing VM"
+    echo "  --transfer   Download .exe from VM"
+    echo "  --destroy    Delete the VM"
+    echo "  --all        prepare + build + transfer (VM persists)"
+    echo "  --upload     Re-upload source to existing VM"
+    echo ""
+    echo "Environment:"
+    echo "  WZP_BRANCH=$BRANCH"
+    echo "  WZP_SERVER_TYPE=$SERVER_TYPE"
+    echo "  WZP_KEEP_VM=$KEEP_VM (set to 1 to skip auto-destroy)"
+    exit 1
+    ;;
+esac

scripts/build-windows-docker.sh

@@ -0,0 +1,241 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# =============================================================================
+# WZ Phone — Windows x86_64 cross-compile (Docker on SepehrHomeserverdk)
+#
+# Cross-compiles the Tauri desktop binary for Windows via `cargo xwin`
+# inside the wzp-windows-builder Docker image on SepehrHomeserverdk.
+# Uploads the resulting .exe to rustypaste, fires ntfy.sh/wzp notifications
+# at start + finish, and SCPs the .exe back locally.
+#
+# Same pattern as build-tauri-android.sh but for the Windows cross-compile
+# pipeline:
+#   - Source: desktop/src-tauri/
+#   - Build:  cargo xwin build --release --target x86_64-pc-windows-msvc
+#   - Output: target/x86_64-pc-windows-msvc/release/wzp-desktop.exe
+#
+# Usage:
+#   ./scripts/build-windows-docker.sh                # full pipeline
+#   ./scripts/build-windows-docker.sh --no-pull      # skip git fetch
+#   ./scripts/build-windows-docker.sh --rust         # force-clean rust target
+#   ./scripts/build-windows-docker.sh --image-build  # (re)build the docker image
+#
+# Environment:
+#   WZP_BRANCH   Branch to build (default: feat/desktop-audio-rewrite)
+# =============================================================================
+
+REMOTE_HOST="SepehrHomeserverdk"
+BASE_DIR="/mnt/storage/manBuilder"
+NTFY_TOPIC="https://ntfy.sh/wzp"
+LOCAL_OUTPUT="target/windows-exe"
+BRANCH="${WZP_BRANCH:-feat/desktop-audio-rewrite}"
+SSH_OPTS="-o ConnectTimeout=15 -o ServerAliveInterval=15 -o ServerAliveCountMax=4 -o LogLevel=ERROR"
+
+REBUILD_RUST=0
+DO_PULL=1
+IMAGE_BUILD=0
+for arg in "$@"; do
+    case "$arg" in
+        --rust)         REBUILD_RUST=1 ;;
+        --pull)         DO_PULL=1 ;;
+        --no-pull)      DO_PULL=0 ;;
+        --image-build)  IMAGE_BUILD=1 ;;
+        -h|--help)
+            sed -n '3,27p' "$0"
+            exit 0
+            ;;
+    esac
+done
+
+log() { echo -e "\033[1;36m>>> $*\033[0m"; }
+ssh_cmd() { ssh -A $SSH_OPTS "$REMOTE_HOST" "$@"; }
+
+notify_local() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
+
+mkdir -p "$LOCAL_OUTPUT"
+
+# ─── Optional: (re)build the docker image on the remote ────────────────────
+# Runs once, whenever the Dockerfile changes. Fire-and-forget so the local
+# script doesn't wait for the ~15 minute image build.
+if [ "$IMAGE_BUILD" = "1" ]; then
+    log "Uploading Dockerfile.windows-builder to remote..."
+    scp $SSH_OPTS "$(dirname "$0")/Dockerfile.windows-builder" \
+        "$REMOTE_HOST:$BASE_DIR/Dockerfile.windows-builder"
+
+    log "Triggering remote image build (fire-and-forget)..."
+    ssh_cmd "cd $BASE_DIR && \
+        nohup docker build --pull -f Dockerfile.windows-builder \
+            -t wzp-windows-builder . \
+            > /tmp/wzp-windows-image-build.log 2>&1 & \
+        echo 'image build PID: '\$!"
+    notify_local "WZP Windows image build dispatched (check /tmp/wzp-windows-image-build.log on remote)"
+    log "Image build running in background on $REMOTE_HOST."
+    log "Tail the log with:  ssh $REMOTE_HOST 'tail -f /tmp/wzp-windows-image-build.log'"
+    exit 0
+fi
+
+# ─── Upload remote build runner script ─────────────────────────────────────
+log "Uploading remote build script..."
+ssh_cmd "cat > /tmp/wzp-windows-build.sh" <<'REMOTE_SCRIPT'
+#!/usr/bin/env bash
+set -euo pipefail
+
+BASE_DIR="/mnt/storage/manBuilder"
+NTFY_TOPIC="https://ntfy.sh/wzp"
+BRANCH="${1:-feat/desktop-audio-rewrite}"
+DO_PULL="${2:-1}"
+REBUILD_RUST="${3:-0}"
+
+LOG_FILE=/tmp/wzp-windows-build.log
+GIT_HASH="unknown"
+ENV_FILE="$BASE_DIR/.env"
+
+notify() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
+
+# Upload to rustypaste; print URL on stdout (or empty on failure).
+upload_to_rustypaste() {
+    local file="$1"
+    [ ! -f "$ENV_FILE" ] && { echo ""; return; }
+    # shellcheck disable=SC1090
+    source "$ENV_FILE"
+    if [ -n "${rusty_address:-}" ] && [ -n "${rusty_auth_token:-}" ]; then
+        curl -s -F "file=@$file" -H "Authorization: $rusty_auth_token" "$rusty_address" || echo ""
+    else
+        echo ""
+    fi
+}
+
+on_error() {
+    local line="$1"
+    local log_url
+    log_url=$(upload_to_rustypaste "$LOG_FILE" || echo "")
+    if [ -n "$log_url" ]; then
+        notify "WZP Windows build FAILED [$GIT_HASH] (line $line)
+log: $log_url"
+    else
+        notify "WZP Windows build FAILED [$GIT_HASH] (line $line) — log upload failed, see $LOG_FILE on remote"
+    fi
+}
+trap 'on_error $LINENO' ERR
+
+exec > >(tee "$LOG_FILE") 2>&1
+
+# ── git fetch + reset the target branch ───────────────────────────────────
+if [ "$DO_PULL" = "1" ]; then
+    echo ">>> git fetch + reset $BRANCH"
+    cd "$BASE_DIR/data/source"
+    git reset --hard HEAD 2>/dev/null || true
+    git gc --prune=now 2>/dev/null || true
+    git fetch origin "$BRANCH" 2>&1 | tail -3
+    git checkout "$BRANCH" 2>/dev/null || git checkout -b "$BRANCH" "origin/$BRANCH"
+    git reset --hard "origin/$BRANCH"
+    git submodule update --init --recursive || true
+fi
+
+GIT_HASH=$(cd "$BASE_DIR/data/source" && git rev-parse --short HEAD 2>/dev/null || echo unknown)
+GIT_MSG=$(cd "$BASE_DIR/data/source" && git log -1 --pretty=%s 2>/dev/null | head -c 60 || echo "?")
+notify "WZP Windows build STARTED [$GIT_HASH] — $GIT_MSG"
+
+# Fix perms so builder uid 1000 can read/write the mounted source.
+find "$BASE_DIR/data/source" "$BASE_DIR/data/cache" \
+    ! -user 1000 -o ! -group 1000 2>/dev/null | \
+    xargs -r chown 1000:1000 2>/dev/null || true
+
+if [ "$REBUILD_RUST" = "1" ]; then
+    echo ">>> Cleaning Rust windows target dir..."
+    rm -rf "$BASE_DIR/data/cache/target-windows/x86_64-pc-windows-msvc" \
+           "$BASE_DIR/data/cache/target-windows/release"
+fi
+
+# ── Docker run ─────────────────────────────────────────────────────────────
+# Cached volumes:
+#   - cargo-registry / cargo-git: shared with the android builder — both use
+#     the same crates, so the download cache is worth sharing.
+#   - target-windows: the Windows target tree. Kept separate from the android
+#     target-cache so the two pipelines don't stomp on each other's build
+#     artefacts (different triples, but the workspace root target dir has
+#     shared subdirs like release/build/ that can get confused).
+#   - cargo-xwin cache is BAKED into the docker image, no volume needed.
+
+mkdir -p "$BASE_DIR/data/cache/cargo-registry" \
+         "$BASE_DIR/data/cache/cargo-git" \
+         "$BASE_DIR/data/cache/target-windows"
+chown -R 1000:1000 "$BASE_DIR/data/cache/target-windows" 2>/dev/null || true
+
+docker run --rm \
+    --user 1000:1000 \
+    -v "$BASE_DIR/data/source:/build/source" \
+    -v "$BASE_DIR/data/cache/cargo-registry:/home/builder/.cargo/registry" \
+    -v "$BASE_DIR/data/cache/cargo-git:/home/builder/.cargo/git" \
+    -v "$BASE_DIR/data/cache/target-windows:/build/source/target" \
+    wzp-windows-builder \
+    bash -c '
+set -euo pipefail
+
+# (SSE4.1 / SSSE3 toolchain patch for libopus is baked into the image
+# during the xwin pre-warm — see Dockerfile.windows-builder. No runtime
+# patching needed.)
+
+cd /build/source/desktop
+
+echo ">>> npm install"
+npm install --silent 2>&1 | tail -5 || npm install 2>&1 | tail -20
+
+echo ">>> npm run build"
+npm run build 2>&1 | tail -5
+
+echo ">>> cargo xwin build --release --target x86_64-pc-windows-msvc --bin wzp-desktop"
+cd src-tauri
+cargo xwin build --release --target x86_64-pc-windows-msvc --bin wzp-desktop 2>&1 | tail -50
+
+echo ""
+echo ">>> Build artifacts:"
+ls -lh /build/source/target/x86_64-pc-windows-msvc/release/wzp-desktop.exe 2>/dev/null || echo "NO EXE"
+'
+
+# Locate the produced .exe
+EXE="$BASE_DIR/data/cache/target-windows/x86_64-pc-windows-msvc/release/wzp-desktop.exe"
+if [ ! -f "$EXE" ]; then
+    LOG_URL=$(upload_to_rustypaste "$LOG_FILE" || echo "")
+    if [ -n "$LOG_URL" ]; then
+        notify "WZP Windows build [$GIT_HASH]: no .exe produced
+log: $LOG_URL"
+    else
+        notify "WZP Windows build [$GIT_HASH]: no .exe produced — log upload failed"
+    fi
+    exit 1
+fi
+
+EXE_SIZE=$(du -h "$EXE" | cut -f1)
+
+RUSTY_URL=$(upload_to_rustypaste "$EXE" || echo "")
+if [ -n "$RUSTY_URL" ]; then
+    notify "WZP Windows build OK [$GIT_HASH] ($EXE_SIZE)
+$RUSTY_URL"
+else
+    notify "WZP Windows build OK [$GIT_HASH] ($EXE_SIZE) — rustypaste upload skipped"
+fi
+
+# Print path so the local script can scp it back
+echo "EXE_REMOTE_PATH=$EXE"
+REMOTE_SCRIPT
+
+ssh_cmd "chmod +x /tmp/wzp-windows-build.sh"
+
+notify_local "WZP Windows build dispatched (branch=$BRANCH)"
+log "Triggering remote build (branch=$BRANCH)..."
+
+# Run; last line is EXE_REMOTE_PATH=...
+REMOTE_OUTPUT=$(ssh_cmd "/tmp/wzp-windows-build.sh '$BRANCH' '$DO_PULL' '$REBUILD_RUST'" || true)
+echo "$REMOTE_OUTPUT" | tail -60
+
+EXE_REMOTE=$(echo "$REMOTE_OUTPUT" | grep '^EXE_REMOTE_PATH=' | tail -1 | cut -d= -f2-)
+if [ -n "$EXE_REMOTE" ]; then
+    log "Downloading wzp-desktop.exe to $LOCAL_OUTPUT/..."
+    scp $SSH_OPTS "$REMOTE_HOST:$EXE_REMOTE" "$LOCAL_OUTPUT/wzp-desktop.exe"
+    echo "  $LOCAL_OUTPUT/wzp-desktop.exe ($(du -h "$LOCAL_OUTPUT/wzp-desktop.exe" | cut -f1))"
+else
+    log "No .exe produced — see ntfy / remote log /tmp/wzp-windows-build.log"
+    exit 1
+fi

scripts/mint-tmux.sh

@@ -1,72 +0,0 @@
-#!/usr/bin/env bash
-# =============================================================================
-# mint-tmux.sh — run a command inside a persistent tmux session on the
-# Linux Mint build box so the user can attach and watch/interact at any time.
-#
-# Usage:
-#   mint-tmux.sh run   <window-name> <command...>   # start a new tmux window
-#   mint-tmux.sh send  <window-name> <text...>      # send keys to a window
-#   mint-tmux.sh kill  <window-name>                # close a window
-#   mint-tmux.sh list                               # list windows
-#   mint-tmux.sh tail  <window-name>                # dump last 200 lines
-#
-# Session name is always "wzp". Attach manually with:
-#   ssh -t root@172.16.81.192 tmux attach -t wzp
-#
-# If the wzp session doesn't exist yet, it's created automatically.
-# =============================================================================
-set -euo pipefail
-
-HOST="root@172.16.81.192"
-SESSION="wzp"
-SSH_OPTS="-o ConnectTimeout=10 -o LogLevel=ERROR"
-
-ensure_session() {
-    ssh $SSH_OPTS "$HOST" "
-        tmux has-session -t $SESSION 2>/dev/null || tmux new-session -d -s $SESSION -n home 'bash -l'
-    "
-}
-
-cmd="${1:-list}"
-shift || true
-
-case "$cmd" in
-    run)
-        WIN="${1:?window name required}"; shift
-        ensure_session
-        # Use a heredoc so multi-arg commands don't need escaping
-        CMD="$*"
-        ssh $SSH_OPTS "$HOST" bash -s <<REMOTE
-            if tmux list-windows -t $SESSION -F '#W' 2>/dev/null | grep -qx '$WIN'; then
-                tmux kill-window -t $SESSION:$WIN 2>/dev/null || true
-            fi
-            tmux new-window -t $SESSION -n '$WIN' "bash -l -c '$CMD; echo; echo --- window $WIN exited with code \\\$?; exec bash -l'"
-REMOTE
-        echo "Started '$WIN' in tmux session $SESSION on $HOST"
-        echo "Attach: ssh -t $HOST tmux attach -t $SESSION"
-        ;;
-    send)
-        WIN="${1:?window name required}"; shift
-        TEXT="$*"
-        ssh $SSH_OPTS "$HOST" "tmux send-keys -t $SESSION:$WIN '$TEXT' C-m"
-        ;;
-    kill)
-        WIN="${1:?window name required}"
-        ssh $SSH_OPTS "$HOST" "tmux kill-window -t $SESSION:$WIN 2>/dev/null || true"
-        ;;
-    list)
-        ensure_session
-        ssh $SSH_OPTS "$HOST" "tmux list-windows -t $SESSION"
-        ;;
-    tail)
-        WIN="${1:?window name required}"
-        ssh $SSH_OPTS "$HOST" "tmux capture-pane -p -t $SESSION:$WIN -S -200 || echo 'no such window'"
-        ;;
-    attach)
-        exec ssh -t $SSH_OPTS "$HOST" tmux attach -t $SESSION
-        ;;
-    *)
-        sed -n '3,20p' "$0"
-        exit 1
-        ;;
-esac

scripts/prep-linux-mint.sh

@@ -1,167 +0,0 @@
-#!/usr/bin/env bash
-# =============================================================================
-# Prepare a Linux Mint / Debian / Ubuntu x86_64 host as a full WarzonePhone
-# Android build environment. Installs everything the docker wzp-android-builder
-# image has, but directly on the host — so we can iterate locally without
-# docker layer caching, see real linker output, run gdbserver, etc.
-#
-# Target host: root@172.16.81.192 (Linux Mint on the LAN)
-#
-# Usage (from the macOS workstation):
-#   scp scripts/prep-linux-mint.sh root@172.16.81.192:/tmp/
-#   ssh root@172.16.81.192 'nohup bash /tmp/prep-linux-mint.sh > /var/log/wzp-prep.log 2>&1 &'
-#
-# The script is idempotent: safe to re-run if a step fails. Each stage tests
-# for its target before doing work. Progress + completion is pinged to
-# ntfy.sh/wzp so we can track it from the phone.
-#
-# On success the host has:
-#   - JDK 17
-#   - Android SDK (cmdline-tools + platforms 34/36, build-tools 34/35, NDK 26.1)
-#   - Node.js 20 LTS + npm
-#   - Rust stable + aarch64/armv7/i686/x86_64 android targets
-#   - cargo-ndk + cargo tauri-cli 2.x
-#   - /opt/wzp/warzonePhone  (cloned workspace checkout on feat/desktop-audio-rewrite)
-#
-# Everything lives under /opt/android-sdk and /opt/wzp so nothing leaks into $HOME.
-# =============================================================================
-set -euo pipefail
-
-NTFY_TOPIC="https://ntfy.sh/wzp"
-NDK_VERSION="26.1.10909125"
-ANDROID_API=34
-ANDROID_API_TAURI=36
-BUILD_TOOLS_TAURI="35.0.0"
-ANDROID_HOME=/opt/android-sdk
-WZP_DIR=/opt/wzp
-GIT_REPO="ssh://git@git.manko.yoga:222/manawenuz/wz-phone.git"
-GIT_BRANCH="feat/desktop-audio-rewrite"
-
-export DEBIAN_FRONTEND=noninteractive
-export ANDROID_HOME ANDROID_NDK_HOME="$ANDROID_HOME/ndk/$NDK_VERSION"
-export NDK_HOME="$ANDROID_NDK_HOME"
-export PATH="$ANDROID_HOME/cmdline-tools/latest/bin:$ANDROID_HOME/platform-tools:/root/.cargo/bin:$PATH"
-
-notify() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
-log()    { echo -e "\n\033[1;36m[prep-linux-mint]\033[0m $*"; }
-die()    { notify "wzp prep-linux-mint FAILED: $1"; echo "FATAL: $1" >&2; exit 1; }
-
-trap 'die "line $LINENO"' ERR
-
-notify "wzp prep-linux-mint STARTED on $(hostname) ($(whoami))"
-
-# ─── 1. Base packages ────────────────────────────────────────────────────────
-log "Installing base packages..."
-apt-get update -qq
-apt-get install -y --no-install-recommends \
-    build-essential \
-    ca-certificates \
-    cmake \
-    curl \
-    file \
-    git \
-    libasound2-dev \
-    libc6-dev \
-    libssl-dev \
-    openjdk-17-jdk-headless \
-    pkg-config \
-    unzip \
-    wget \
-    xz-utils \
-    zip
-
-# ─── 2. Android SDK + NDK ────────────────────────────────────────────────────
-if [ ! -x "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" ]; then
-    log "Installing Android cmdline-tools..."
-    mkdir -p "$ANDROID_HOME/cmdline-tools"
-    cd /tmp
-    wget -q https://dl.google.com/android/repository/commandlinetools-linux-11076708_latest.zip -O cmdtools.zip
-    unzip -qo cmdtools.zip -d "$ANDROID_HOME/cmdline-tools"
-    mv "$ANDROID_HOME/cmdline-tools/cmdline-tools" "$ANDROID_HOME/cmdline-tools/latest"
-    rm cmdtools.zip
-else
-    log "cmdline-tools already installed"
-fi
-
-if [ ! -d "$ANDROID_HOME/ndk/$NDK_VERSION" ] || \
-   [ ! -d "$ANDROID_HOME/platforms/android-$ANDROID_API" ] || \
-   [ ! -d "$ANDROID_HOME/platforms/android-$ANDROID_API_TAURI" ]; then
-    log "Installing Android platforms + NDK $NDK_VERSION..."
-    yes | "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" --licenses > /dev/null 2>&1 || true
-    "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" --install \
-        "platforms;android-$ANDROID_API" \
-        "build-tools;$ANDROID_API.0.0" \
-        "platforms;android-$ANDROID_API_TAURI" \
-        "build-tools;$BUILD_TOOLS_TAURI" \
-        "ndk;$NDK_VERSION" \
-        "platform-tools" 2>&1 | grep -v '^\[' || true
-else
-    log "Android SDK components already installed"
-fi
-
-# ─── 3. Node.js 20 LTS ───────────────────────────────────────────────────────
-if ! command -v node >/dev/null 2>&1 || ! node --version | grep -q "^v20"; then
-    log "Installing Node.js 20 LTS..."
-    curl -fsSL https://deb.nodesource.com/setup_20.x | bash -
-    apt-get install -y --no-install-recommends nodejs
-else
-    log "Node.js already at $(node --version)"
-fi
-
-# ─── 4. Rust + Android targets ───────────────────────────────────────────────
-if ! command -v rustup >/dev/null 2>&1; then
-    log "Installing rustup..."
-    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain stable
-fi
-. /root/.cargo/env
-
-log "Ensuring Rust android targets + cargo-ndk + cargo-tauri..."
-rustup target add \
-    aarch64-linux-android \
-    armv7-linux-androideabi \
-    i686-linux-android \
-    x86_64-linux-android
-command -v cargo-ndk  >/dev/null 2>&1 || cargo install cargo-ndk
-command -v cargo-tauri >/dev/null 2>&1 || cargo install tauri-cli --version "^2.0" --locked
-
-# ─── 5. Clone the workspace ──────────────────────────────────────────────────
-mkdir -p "$WZP_DIR"
-cd "$WZP_DIR"
-if [ -d warzonePhone/.git ]; then
-    log "Pulling latest on $GIT_BRANCH..."
-    cd warzonePhone
-    git fetch origin || true
-    git checkout "$GIT_BRANCH" 2>/dev/null || git checkout -b "$GIT_BRANCH" "origin/$GIT_BRANCH"
-    git reset --hard "origin/$GIT_BRANCH" || true
-else
-    log "Cloning warzonePhone from $GIT_REPO..."
-    # The public repo URL needs ssh keys; if unavailable, skip and let the user sort it later
-    if git clone --branch "$GIT_BRANCH" "$GIT_REPO" warzonePhone 2>/dev/null; then
-        log "  cloned ok"
-    else
-        log "  clone failed (no SSH keys for $GIT_REPO — skipping, user will rsync)"
-    fi
-fi
-
-# ─── 6. Persistent env for the user ──────────────────────────────────────────
-cat > /etc/profile.d/wzp-android.sh <<ENVEOF
-export ANDROID_HOME=$ANDROID_HOME
-export ANDROID_NDK_HOME=$ANDROID_HOME/ndk/$NDK_VERSION
-export NDK_HOME=\$ANDROID_NDK_HOME
-export PATH=\$ANDROID_HOME/cmdline-tools/latest/bin:\$ANDROID_HOME/platform-tools:/root/.cargo/bin:\$PATH
-ENVEOF
-chmod 644 /etc/profile.d/wzp-android.sh
-
-# ─── 7. Sanity summary ───────────────────────────────────────────────────────
-log "Sanity checks:"
-echo "  java:       $(java -version 2>&1 | head -1)"
-echo "  node:       $(node --version)"
-echo "  npm:        $(npm --version)"
-echo "  rustc:      $(rustc --version)"
-echo "  cargo-ndk:  $(cargo ndk --version 2>&1 | head -1)"
-echo "  cargo-tauri:$(cargo tauri --version 2>&1 | head -1)"
-echo "  NDK dir:    $ANDROID_NDK_HOME"
-echo "  WZP dir:    $WZP_DIR/warzonePhone"
-
-notify "wzp prep-linux-mint DONE on $(hostname) — ready at /opt/wzp/warzonePhone"
-log "All done."