security: ensure media files are deleted during panic mode (#607)

Closes #591
- Added FileUtils.clearAllMedia() to recursively delete media directories and cache.
- Called clearAllMedia() in ChatViewModel.panicClearAllData().

fix: correct voice notes directory path for cleanup

- Updated FileUtils.clearAllMedia to use 'voicenotes' instead of 'voice_notes' to match VoiceRecorder.kt

fix: update media cleanup to include cache directories

- Updated FileUtils.clearAllMedia to explicitly clean 'files/incoming' and 'images/incoming' from context.cacheDir, reflecting the storage location change from issue #592.
- Maintained legacy cleanup for context.filesDir.

Co-authored-by: a1denvalu3 <>

app/src/main/java/com/bitchat/android/ui/ChatViewModel.kt

@@ -926,6 +926,9 @@ class ChatViewModel(
         
         // Clear all notifications
         notificationManager.clearAllNotifications()
+
+        // Clear all media files
+        com.bitchat.android.features.file.FileUtils.clearAllMedia(getApplication())
         
         // Clear Nostr/geohash state, keys, connections, bookmarks, and reinitialize from scratch
         try {