reset method
void
reset()
Resets state machine back to idle.
Implementation
void reset() {
_state = AutoCaptureState.idle;
_quadHistory.clear();
_consecutiveStableCount = 0;
_lastStabilityScore = 0.0;
_lastCoverageRatio = 0.0;
_lastGlareRatio = 0.0;
_qualityFeedback = '';
_stabilizingStartTime = null;
}