- Add MIN_PWM_PERCENT (20%) to ensure motor starts reliably
- Add CURRENT_CALIBRATION factor (0.33) for accurate current readings
- Add stall-based return option for pingpong mode (returns on stall instead of time)
- Update stall detection: 7A threshold, 1000ms confirm time
- Add DISABLE_STALL_DETECT config option
- Keep last speed setting when motor stops (UI improvement)
- Update webserver UI with 'Return on stall only' checkbox