1. **Hardware switch**: Replaced backlight PWM control (GPIO 22) with WS2812B RGB LED (GPIO 8)
- Removed analog brightness levels (0-255)
- Added bit-bang WS2812B protocol implementation (`setRGB()`)
- Defined color palette: RED, GREEN, BLUE, WHITE, OFF
2. **Visual feedback improvements**:
- **Silent state**: LED OFF (was dim backlight)
- **Alarm state**: Blinks RED/WHITE (was full brightness on/off)
- **Button press**: Shows WHITE while held (was full brightness)
- **Confirmations**: Green flash for SILENCE commands (was dim flash)
3. **Bug fixes**:
- Added edge detection for button to prevent repeated triggers
- Added explicit LED OFF commands throughout setup to prevent lingering states
- Button release now properly resets ALARM → SILENT
4. **Code cleanup**: Removed section divider comments, condensed enum/constant declarations
5. **Tooling**: Added `mise.toml` task for monitor-only (`mon`)
- **More visible alerts**: RGB colors provide clearer state indication than brightness levels
- **Better reliability**: Explicit state management prevents LED staying on unintentionally
- **Improved UX**: Button can now manually cancel alarms with visual confirmation
