Add ESP32-S3 BLE-to-RS422 bridge firmware for Carryout G2

NimBLE-based Nordic UART Service (NUS) bridge on ESP32-S3-DevKitC-1.
Transparent passthrough: BLE client writes → UART1 TX → RS-422 → G2,
and G2 → RS-422 → UART1 RX → BLE notifications. USB serial serves as
debug monitor and fallback input.

Uses two MAX485 modules (one locked TX, one locked RX) with a SparkFun
BSS138 level converter for 3.3V/5V translation. Wiring schematic and
RJ-12 pinout documented in docs/ble-bridge-wiring.md.

firmware/ble-bridge/platformio.ini

@@ -0,0 +1,21 @@
+; ESP32-S3 BLE-to-RS422 Bridge for Winegard Carryout G2
+; Transparent NUS (Nordic UART Service) serial bridge
+
+[env:esp32s3]
+platform = espressif32
+board = esp32-s3-devkitc-1
+framework = arduino
+
+; NimBLE for BLE (lighter than BlueDroid), NeoPixel for status LED
+lib_deps =
+    h2zero/NimBLE-Arduino@^2.1
+    adafruit/Adafruit NeoPixel@^1.12
+
+build_flags =
+    -DBOARD_HAS_PSRAM
+    -DBOARD_HAS_PSRAM_OPI
+    ; Serial via CP2102N UART0 port, not USB-CDC
+    -DARDUINO_USB_CDC_ON_BOOT=0
+
+monitor_speed = 115200
+upload_speed = 921600