feat(ios): add audio keep-alive utilities

ios/zeus/NWCAudioKeepAlive.h

@@ -4,13 +4,6 @@
 /**
  * NWCAudioKeepAlive
  *
- * Experimental iOS module that uses AVAudioSession (.playback category) and a
- * looping silent AVAudioEngine buffer to keep the app alive in the background,
- * enabling persistent WebSocket (Nostr relay / NWC) connections.
- *
- * NOTE: This technique is for experimentation only and may be rejected by App
- * Store review if the audio session is deemed non-functional.
- *
  * Emitted events (listen via NativeEventEmitter):
  *   - NWCAudioInterrupted       Audio session was interrupted (e.g. phone call)
  *   - NWCAudioInterruptionEnded Audio interruption ended; session will resume

ios/zeus/NWCAudioKeepAlive.m

@@ -83,7 +83,6 @@ RCT_EXPORT_MODULE();
     [self unregisterNotifications];
 }
 
-// ─── Exported methods ────────────────────────────────────────────────────────
 
 /**
  * Configures AVAudioSession with .playback category (mixWithOthers so we