Felt Orbit ORHACK demo v20 - Gate + corrected latch

Base: v19.
Only additional change:
  samp_mode 2 (Trigger) -> samp_mode 1 (Gate)

Kept:
- confirmed fixed sample length: 217956 frames
- corrected latch note-off handling using stripnote
- AUX edge toggle
- pitch/octave unchanged

This is deliberately a diagnostic build.
Expected distinction:
Latch OFF: releasing a key should release/stop the note.
Latch ON: key-up is swallowed, so the note/sample continues.
Turning latch OFF flushes the stored note-offs.

No release shaping has been added yet.
