Refactor shot clock state handling

[whywaita]

Summary

• replace the global timer vars with a ShotClock struct that tracks timing, flashing, and alarm state
• update the touch handling to reset, start, and stop based on shot clock status
• keep the display in sync with timer flashes and show time up messaging

Testing

• not run (hardware dependent)

[Copilot]

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

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[Copilot]

The loop delay was reduced from 1000ms to 10ms, which increases CPU usage 100x. Since the timer only needs second-level precision and flash updates occur every 500ms, consider using a delay of at least 100ms to balance responsiveness with power efficiency.

Suggested change

	delay(10);
	delay(100);

[Copilot]

The drift correction logic assumes secondsPassed is always 1 in normal operation. If the device experiences significant lag (e.g., >2 seconds), remaining could underflow. Consider adding a bounds check: remaining = max(0, remaining - secondsPassed) or limiting secondsPassed to prevent unexpected behavior.

[Copilot]

The label is redundantly extracted from the same button that was just assigned to activeButton. Since activeButton.label already contains the correct label, this line can be simplified to const char* label = activeButton.label;

Suggested change

	const char* label = shotClock.timeUp ? resetButton.label : stopButton.label;
	const char* label = activeButton.label;