Introduce `VCC_MV` to `funconfig.h` for consistent voltage readings.
Add `get_current_ma` function to `main.c` for clearer current
calculations.
Remove unused `PIN_LED` and `Delay_Ms(5000)` from `main.c`.
Update VBUS voltage calculation to use `VCC_MV`.
Print TIP sensor voltage in millivolts instead of raw ADC values.
