fix(android): wire speaker mute to TalkMode, release audio focus on stop

- Codex P1: setSpeakerEnabled now syncs talkMode.setPlaybackEnabled
  so muting the speaker works when ttsOnAllResponses is active.
- Codex P2: abandonAudioFocus() called in stopSpeaking to prevent
  audio focus leak after TTS completes or is interrupted.

apps/android/app/src/main/java/ai/openclaw/android/NodeRuntime.kt

@@ -696,6 +696,8 @@ class NodeRuntime(context: Context) {
     if (voiceReplySpeakerLazy.isInitialized()) {
       voiceReplySpeaker.setPlaybackEnabled(value)
     }
+    // Keep TalkMode in sync so speaker mute works when ttsOnAllResponses is active.
+    talkMode.setPlaybackEnabled(value)
   }
 
   fun refreshGatewayConnection() {