Stability and polish for the live charging feature introduced in 1.0.0.

Changed:
- Live Charge Screen: SoC now displayed as a large hero number

Fixed:
- Live charge screen closes automatically when charging stops
- Charging notification correctly opens main screen on older TM APIs
- Charging gauge arrow hidden when live charge is unavailable
- V/A chart uses distinct colors (amber and blue)
- Stats for Nerds: missing values when filtering by year
