- Add Flask backend with SocketIO for real-time updates
- Implement sensor service with mock data generation
- Create Dashboard UI with rainfall, voltage, status displays
- Create Settings UI with station, network, ADC, sensor configuration
- Create Calibration UI with live ADC readings and rainfall reset
- Touch-optimized interface with 64px touch targets for 7" display
Implements: DASH-01 through DASH-09, UI-01 through UI-03,
SETT-01 through SETT-08, CAL-01 through CAL-04, BACK-01 through BACK-03
