v191 + key stars transplanted from v209

- Keeps v191 raw host-knob mapping unchanged.
- Adds the v209 five-slot latch/AUX key-star behavior to felt_manta_visual.
- Note-on while visual latch is ON activates one of five 1x1 star positions sequentially.
- Each slot uses its own retriggerable delay 4800 timer.
- Bridges felt_latch outlet 1 to $0-felt-visual-latch.
- Keeps v191 permanent background star pixels (does not apply v209 frame-budget removal of five background points).
- No extra gFlip and no key-triggered redraw added.
