- NodeClient now persists RSA key pair to SharedPreferences
- Device ID derived from SHA-256 hash of public key
- Stable identity across app restarts
- SettingsRepository nodeId is now just display name

- CameraService: photo capture, video recording (Camera2 API)
- MicrophoneService: audio recording, voice messages
- AudioPlaybackService: play audio from file/URI/base64
- ClipboardService: copy/paste text and URIs
- UsageStatsService: foreground app, recent apps
- Updated memory/PROJECT_STATUS.md with full status