loop - repeat a section of your pattern on the fly during performance

why use this:
- build-ups and breakdowns
- DJ-style beat juggling
- extend a section while you figure out what's next

activate loop mode:
[shift] + [tempo]

controls:
- x-knob: loop length (shorter = tighter loop, down to 1/16 stutter)
- y-knob: loop position (which part of the pattern to loop)

exit loop:
- tap [tempo]: exits immediately (hard cut)
- tap [main]: exits at next bar (smooth, quantized exit)

this is a LIVE performance tool only
the loop doesn't record - it's for real-time performance manipulation