- Replace Cairo DrawingArea with custom NesScreen widget using
GskTextureScaleNode for GPU-accelerated nearest-neighbor rendering
- Migrate from FileChooserNative to FileDialog (GTK 4.10+)
- Add AlertDialog for error display, structured logging via env_logger
- Add FPS counter (F3), NTSC/PAL toggle (F7), fullscreen (F11),
Esc to quit, save/load state (Ctrl+S/L), volume slider
- Add player 2 keyboard input support
- Fix window proportions by compensating for header bar height
- CpalAudioSink writes to SPSC ring buffer, cpal callback reads
- Graceful fallback to silent operation on audio device errors
- Volume slider (0-100%) in header bar with speaker icon
- Ring buffer cleared on ROM load and reset