feat: relay ping handling, identity persistence, linux build script (backport)

Backported from feat/android-voip-client:
- Relay: SNI "ping" connections handled gracefully (no timeout errors)
- Relay: identity persisted in ~/.wzp/relay-identity (stable fingerprint)
- Linux fire-and-forget build script (Hetzner VM)

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

crates/wzp-relay/Cargo.toml

@@ -28,6 +28,7 @@ prometheus = "0.13"
 axum = { version = "0.7", default-features = false, features = ["tokio", "http1", "ws"] }
 tower-http = { version = "0.6", features = ["fs"] }
 futures-util = "0.3"
+dirs = "6"
 
 [[bin]]
 name = "wzp-relay"

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};
+use tracing::{error, info, warn};
 
 use wzp_proto::MediaTransport;
 use wzp_relay::config::RelayConfig;
@@ -207,8 +207,39 @@ async fn main() -> anyhow::Result<()> {
         tokio::spawn(wzp_relay::metrics::serve_metrics(port, m, p, rr));
     }
 
-    // Generate ephemeral relay identity for crypto handshake
-    let relay_seed = wzp_crypto::Seed::generate();
+    // Load or generate relay identity — persisted in ~/.wzp/relay-identity
+    let relay_seed = {
+        let config_dir = dirs::home_dir()
+            .unwrap_or_else(|| std::path::PathBuf::from("."))
+            .join(".wzp");
+        let identity_path = config_dir.join("relay-identity");
+        if identity_path.exists() {
+            if let Ok(hex) = std::fs::read_to_string(&identity_path) {
+                if let Ok(s) = wzp_crypto::Seed::from_hex(hex.trim()) {
+                    info!("loaded relay identity from {}", identity_path.display());
+                    s
+                } else {
+                    warn!("corrupt relay identity file, generating new");
+                    let s = wzp_crypto::Seed::generate();
+                    let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+                    let _ = std::fs::write(&identity_path, &hex);
+                    s
+                }
+            } else {
+                let s = wzp_crypto::Seed::generate();
+                let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+                let _ = std::fs::write(&identity_path, &hex);
+                s
+            }
+        } else {
+            let s = wzp_crypto::Seed::generate();
+            let _ = std::fs::create_dir_all(&config_dir);
+            let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+            let _ = std::fs::write(&identity_path, &hex);
+            info!("generated relay identity at {}", identity_path.display());
+            s
+        }
+    };
     let relay_fp = relay_seed.derive_identity().public_identity().fingerprint;
     info!(addr = %config.listen_addr, fingerprint = %relay_fp, "WarzonePhone relay starting");
 
@@ -299,6 +330,13 @@ async fn main() -> anyhow::Result<()> {
 
             let transport = Arc::new(wzp_transport::QuinnTransport::new(connection));
 
+            // Ping connections: client just measures QUIC connect RTT.
+            // No handshake, no streams — client closes immediately after connecting.
+            if room_name == "ping" {
+                info!(%addr, "ping connection (RTT probe)");
+                return;
+            }
+
             // Probe connections use SNI "_probe" to identify themselves.
             // They skip auth + handshake and just do Ping->Pong + presence gossip.
             if room_name == "_probe" {

scripts/build-linux-notify.sh

@@ -0,0 +1,122 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Build WarzonePhone Linux x86_64 binaries via Hetzner Cloud VPS.
+# Fire and forget — notifies via ntfy.sh/wzp with rustypaste URL.
+#
+# Usage:
+#   ./scripts/build-linux-notify.sh              Full: create VM → build → upload → notify → destroy
+#   ./scripts/build-linux-notify.sh --keep       Keep VM after build
+#   ./scripts/build-linux-notify.sh --pull       Git pull (for existing VM)
+
+SSH_KEY_NAME="wz"
+SSH_KEY_PATH="/Users/manwe/CascadeProjects/wzp"
+SERVER_TYPE="cx33"
+IMAGE="debian-12"
+SERVER_NAME="wzp-linux-builder"
+NTFY_TOPIC="https://ntfy.sh/wzp"
+LOCAL_OUTPUT="target/linux-x86_64"
+PROJECT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+
+SSH_OPTS="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o ConnectTimeout=15 -o ServerAliveInterval=15 -o LogLevel=ERROR"
+
+KEEP_VM=0
+DO_PULL=0
+for arg in "$@"; do
+    case "$arg" in
+        --keep) KEEP_VM=1 ;;
+        --pull) DO_PULL=1 ;;
+    esac
+done
+
+log() { echo -e "\033[1;36m>>> $*\033[0m"; }
+err() { echo -e "\033[1;31mERROR: $*\033[0m" >&2; }
+
+get_vm_ip() {
+    hcloud server list -o columns=name,ipv4 -o noheader 2>/dev/null | grep "$SERVER_NAME" | awk '{print $2}' | tr -d ' '
+}
+
+ssh_cmd() {
+    local ip=$(get_vm_ip)
+    [ -n "$ip" ] || { err "No VM found"; exit 1; }
+    ssh $SSH_OPTS -i "$SSH_KEY_PATH" "root@$ip" "$@"
+}
+
+notify() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
+
+# --- Create VM if needed ---
+existing=$(hcloud server list -o columns=name -o noheader 2>/dev/null | grep "$SERVER_NAME" | tr -d ' ' || true)
+if [ -z "$existing" ]; then
+    log "Creating Hetzner VM ($SERVER_TYPE, $IMAGE)..."
+    hcloud server create --name "$SERVER_NAME" --type "$SERVER_TYPE" --image "$IMAGE" --ssh-key "$SSH_KEY_NAME" --location fsn1 --quiet
+
+    log "Waiting for SSH..."
+    ip=$(get_vm_ip)
+    for i in $(seq 1 30); do
+        ssh $SSH_OPTS -i "$SSH_KEY_PATH" "root@$ip" "echo ok" &>/dev/null && break
+        sleep 2
+    done
+
+    log "Installing deps..."
+    ssh_cmd "apt-get update -qq && apt-get install -y -qq build-essential cmake pkg-config libasound2-dev libssl-dev curl git > /dev/null 2>&1"
+    ssh_cmd "curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain stable > /dev/null 2>&1"
+fi
+
+# --- Upload source ---
+log "Uploading source..."
+ip=$(get_vm_ip)
+rsync -az --delete \
+    --exclude='target' --exclude='.git' --exclude='.claude' \
+    --exclude='node_modules' --exclude='dist' --exclude='android/app/build' \
+    -e "ssh $SSH_OPTS -i $SSH_KEY_PATH" \
+    "$PROJECT_DIR/" "root@$ip:/root/wzp-build/"
+
+# --- Build ---
+log "Building all binaries..."
+notify "WZP Linux build started..."
+
+ssh_cmd "source ~/.cargo/env && cd /root/wzp-build && \
+    cargo build --release --bin wzp-relay --bin wzp-client --bin wzp-web --bin wzp-bench 2>&1 | tail -5 && \
+    echo '--- audio client ---' && \
+    cargo build --release --bin wzp-client --features audio 2>&1 | tail -3 && \
+    cp target/release/wzp-client target/release/wzp-client-audio && \
+    cargo build --release --bin wzp-client 2>&1 | tail -3 && \
+    echo 'BUILD_DONE' && \
+    ls -lh target/release/wzp-relay target/release/wzp-client target/release/wzp-client-audio target/release/wzp-web target/release/wzp-bench"
+
+# --- Package + upload to rustypaste ---
+log "Packaging and uploading..."
+UPLOAD_URL=$(ssh_cmd "cd /root/wzp-build && \
+    tar czf /tmp/wzp-linux-x86_64.tar.gz \
+        -C target/release wzp-relay wzp-client wzp-client-audio wzp-web wzp-bench \
+        -C /root/wzp-build/crates/wzp-web/static index.html audio-processor.js 2>/dev/null && \
+    curl -s -F 'file=@/tmp/wzp-linux-x86_64.tar.gz' \
+        -H 'Authorization: DAxAAGghkn1WKv1+RpPKkg==' \
+        https://paste.dk.manko.yoga")
+
+if [ -n "$UPLOAD_URL" ]; then
+    notify "WZP Linux binaries ready! $UPLOAD_URL"
+    log "Uploaded: $UPLOAD_URL"
+else
+    notify "WZP Linux build FAILED"
+    err "Upload failed"
+fi
+
+# --- Transfer locally ---
+log "Downloading binaries..."
+mkdir -p "$LOCAL_OUTPUT"
+for bin in wzp-relay wzp-client wzp-client-audio wzp-web wzp-bench; do
+    scp $SSH_OPTS -i "$SSH_KEY_PATH" "root@$ip:/root/wzp-build/target/release/$bin" "$LOCAL_OUTPUT/$bin" 2>/dev/null
+done
+ls -lh "$LOCAL_OUTPUT"/wzp-*
+
+# --- Cleanup ---
+if [ "$KEEP_VM" = "1" ]; then
+    log "VM kept alive. Destroy: hcloud server delete $SERVER_NAME"
+else
+    log "Destroying VM..."
+    hcloud server delete "$SERVER_NAME"
+fi
+
+log "Done!"
+echo "  Deploy: scp $LOCAL_OUTPUT/wzp-relay user@server:~/wzp/"