Update docs and firmware for ESPHome bridge migration

- Replace gauge.py (MicroPython) references with gaugecontroller.yaml (ESPHome)
- Update CLAUDE.md and README.md to document ESPHome-native API integration
- Update LED wiring docs for separate main/indicator strips (D22/D36)
- Refactor Arduino firmware to drive two WS2812 strips independently
- Add per-gauge physical offset caching for main and indicator LEDs
- Frame-limit breathe effect (16ms) to reduce unnecessary strip refreshes

wiring.md

@@ -163,19 +163,22 @@ Also connect:
 
 If your driver boards need separate motor power, supply that from the proper motor supply. Do not power motors from the Mega `5V` pin.
 
-## WS2812B LED Strip
+## WS2812 LED Strips
 
-The current sketch expects one shared WS2812B chain.
+The current sketch expects two LED data chains. Backlight and status LEDs stay
+on the main strip; the red/green dial indicator LEDs are on their own strip.
 
-| Mega Pin | WS2812B |
+| Mega Pin | LED Strip |
 |---|---|
-| `D22` | `DIN` |
-| `5V` | `5V` |
-| `GND` | `GND` |
+| `D22` | main backlight/status `DIN` |
+| `D36` | indicator `DIN` |
+| `5V` | both strips `5V` |
+| `GND` | both strips `GND` |
 
 Notes:
 
-- the code expects `7 LEDs per gauge`, so `21 LEDs total`
+- the command protocol still exposes `7 LEDs per gauge`
+- logical indices `0-2` are backlight, `3-4` are indicators, and `5-6` are status
 - use a proper 5V supply sized for the LED current
 - keep LED ground common with the Mega