v0.0.35: WASM create_call_signal, selectable identity, web sections

FC-P3-T2: WASM create_call_signal() export
- Accepts signal_type string (offer/answer/hangup/etc), payload, target
- Returns bincode WireMessage::CallSignal bytes for WS send

FC-P3-T9: Selectable identity display in web
- ETH address shown in code-style block, click to copy
- addSys() gains rawHtml parameter for rich content

FC-P3-T5: Section navigation comments in web.rs
- 5 section markers: State, Crypto, Network, UI, Commands

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

warzone/crates/warzone-wasm/src/lib.rs

@@ -627,6 +627,46 @@ pub fn create_sender_key_from_distribution(
     Ok(hex::encode(encoded))
 }
 
+/// Create a CallSignal WireMessage for sending via WebSocket.
+///
+/// Arguments:
+/// - identity: the WasmIdentity of the sender
+/// - signal_type: "offer" | "answer" | "ice_candidate" | "hangup" | "reject" | "ringing" | "busy"
+/// - payload: SDP offer/answer, ICE candidate JSON, or empty string
+/// - target: recipient fingerprint or group name
+///
+/// Returns: bincode-serialized WireMessage bytes
+#[wasm_bindgen]
+pub fn create_call_signal(
+    identity: &WasmIdentity,
+    signal_type: &str,
+    payload: &str,
+    target: &str,
+) -> Result<Vec<u8>, JsValue> {
+    use warzone_protocol::message::{CallSignalType, WireMessage};
+
+    let st = match signal_type.to_lowercase().as_str() {
+        "offer" => CallSignalType::Offer,
+        "answer" => CallSignalType::Answer,
+        "ice_candidate" | "icecandidate" => CallSignalType::IceCandidate,
+        "hangup" => CallSignalType::Hangup,
+        "reject" => CallSignalType::Reject,
+        "ringing" => CallSignalType::Ringing,
+        "busy" => CallSignalType::Busy,
+        _ => return Err(JsValue::from_str(&format!("unknown signal type: {}", signal_type))),
+    };
+
+    let wire = WireMessage::CallSignal {
+        id: uuid::Uuid::new_v4().to_string(),
+        sender_fingerprint: identity.pub_id.fingerprint.to_string(),
+        signal_type: st,
+        payload: payload.to_string(),
+        target: target.to_string(),
+    };
+
+    bincode::serialize(&wire).map_err(|e| JsValue::from_str(&format!("serialize: {}", e)))
+}
+
 // Tests live in warzone-protocol to avoid js-sys dependency issues.
 // See warzone-protocol/src/x3dh.rs tests for web-client simulation.