feat: add Style tab with theme toggle, custom font settings, and separate color pickers for timer and end message Introduced the Style tab alongside Timer Settings Added theme switcher (light/dark) affecting the control panel only Added font family selector (applies to display) Added individual color pickers for the timer and end message Applied styles via BroadcastChannel to display.html Ensured theme persists via localStorage - Updated layout to support inline color pickers in one row
Fixed a minor bug
