notepat: simpler hold (enter/backspace), add insert as tape key
HOLD rewrite:
- Enter key: snapshot currently-playing notes into heldKeys (press again
to add more notes to the hold set as you play).
- Backspace: clear all held notes.
- New notes never auto-latch — you can freely riff on top of the held
chord without sticking every note. Only explicit Enter press commits
a note to sustain.
- Remove F11/F10 bindings and the f11Held flourish-mode logic.
- HOLD indicator now shows count ("H:3") instead of just "HOLD", and
only appears when there's actually something held.
Tape recording:
- Insert and Pause now also toggle tape recording (alongside PrintScreen)
as fallbacks for laptops where PrtSc doesn't fire standalone.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>