Felt Orbit v191 + v209 KEY-STARS / OLED FRAME-BUDGET FIX

Base: v191 STARS RAW HOST KNOBS.
Kept: v191 raw host-knob behavior.
Imported from v209 visual path:
- five retriggerable 4.8 s key-star slots while AUX visual latch is active
- key events only update star state; stars are emitted by the normal visual frame path
- OLED frame budget reserve: five low-priority 1-pixel background stars removed from BOTH vibration phases
- no extra gFlip and no key-triggered redraw

Target symptom: vibration/display stutter after roughly the 4th-5th rapid key-down.
