feat(ios,p0): iOS P0 platform, audio fixes, channel UX

apps/chanora_flutter/lib/src/rust/api.dart

@@ -41,6 +41,19 @@ Future<void> disconnect() => RustLib.instance.api.crateApiDisconnect();
 /// True if a connection is currently active.
 Future<bool> isConnected() => RustLib.instance.api.crateApiIsConnected();
 
+/// Handle iOS AVAudioSession route changes (SDD-100).
+void handleRouteChange() => RustLib.instance.api.crateApiHandleRouteChange();
+
+/// Handle iOS AVAudioSession interruption begin (SDD-101).
+void handleInterruptionBegan() =>
+    RustLib.instance.api.crateApiHandleInterruptionBegan();
+
+/// Handle iOS AVAudioSession interruption end (SDD-101).
+void handleInterruptionEnded({required bool shouldResume}) => RustLib
+    .instance
+    .api
+    .crateApiHandleInterruptionEnded(shouldResume: shouldResume);
+
 /// Set the push-to-talk state.
 ///
 /// Superseded in v1 by [`set_transmit_mode`] + the binding capture
@@ -427,6 +440,15 @@ sealed class BridgeEvent with _$BridgeEvent {
     /// Current release-tail in milliseconds (0..=500).
     required int releaseTailMs,
   }) = BridgeEvent_VoiceState;
+
+  /// iOS audio interruption state (SDD-101).
+  const factory BridgeEvent.interruptionState({
+    /// True when interruption began, false when it ended.
+    required bool began,
+
+    /// Resume recommendation from the platform. False on begin.
+    required bool shouldResume,
+  }) = BridgeEvent_InterruptionState;
 }
 
 /// Coarse OS-reported network state. Mirrors