fix(android): request microphone permission on startup

apps/chanora_flutter/lib/main.dart

@@ -328,10 +328,22 @@ class _BetaHomeState extends State<_BetaHome> {
     _androidPermissions.recordAudioState.addListener(
       _onRecordAudioPermissionChanged,
     );
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      unawaited(_requestRecordAudioOnStartup());
+    });
     unawaited(_reloadBookmarks());
     unawaited(_hydratePttBinding());
   }
 
+  Future<void> _requestRecordAudioOnStartup() async {
+    try {
+      await _androidPermissions.ensureRecordAudio();
+    } catch (_) {
+      // Best-effort startup prompt only. The join path still gates on
+      // ensureRecordAudio() and applies the listen-only hard-mute policy.
+    }
+  }
+
   void _onRecordAudioPermissionChanged() {
     if (_androidPermissions.recordAudioState.value ==
         AndroidRecordAudioPermissionState.granted) {