docs(ios-audio): align activation lifecycle comments

apps/chanora_flutter/ios/Runner/AppDelegate.swift

@@ -46,7 +46,8 @@ import AVFoundation
     //
     // VoIP configuration is engaged on voice-channel join via the
     // `chanora/ios_audio_session` MethodChannel, driven from Dart
-    // by the BridgeEvent::AudioStarted / AudioStopped lifecycle.
+    // before `voiceJoin` starts VoiceProcessingIO and again as an
+    // idempotent guard on the AudioStarted lifecycle.
     do {
       try AVAudioSession.sharedInstance().setCategory(.ambient, mode: .default)
       logAudioSessionState(context: "launch-ambient")
@@ -79,8 +80,8 @@ import AVFoundation
   }
 
   /// Activate the VoIP audio session. Called from Dart via the
-  /// `chanora/ios_audio_session` channel when a voice channel join
-  /// reaches the `BridgeEvent::AudioStarted` stage. Configures
+  /// `chanora/ios_audio_session` channel before a voice channel join
+  /// starts VoiceProcessingIO. Configures
   /// .playAndRecord + .voiceChat with .mixWithOthers so other apps
   /// (Spotify, podcasts) can keep playing alongside the voice
   /// channel — matching the Telegram group-call UX. Idempotent:

apps/chanora_flutter/lib/services/ios_audio_session_controller.dart

@@ -10,9 +10,9 @@ const iosAudioSessionChannelName = 'chanora/ios_audio_session';
 /// launch and leaves it inactive. The session is only switched to
 /// `.playAndRecord` + `.voiceChat` (with `.mixWithOthers`) while a
 /// voice channel is actually active. This controller is the Dart
-/// side of that contract — call [activate] when the Rust engine
-/// emits `BridgeEvent::AudioStarted` and [deactivate] on
-/// `BridgeEvent::AudioStopped`.
+/// side of that contract — call [activate] before the Rust engine
+/// starts VoiceProcessingIO and [deactivate] on
+/// `BridgeEvent::AudioStopped` or failed joins.
 ///
 /// On non-iOS platforms both methods are no-ops; the platforms
 /// handle their own session lifecycle elsewhere (Android via