feat: notepat metronome F9, sonic awareness for 3x escape
- Metronome moved from F12 to F9 (no Fn key required)
- 3x escape now has rich sonic feedback:
- 1: low 220Hz tone + speak "one"
- 2: rising 330→440Hz + speak "two"
- 3: descending E5→C5→G4 chord + speak "exit"
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>