fix(boards): align LED indices and add docs for corvon 743v1 (#26699)

* boards: corvon 743v1 support (Docs and LED alignment)

This PR addresses #24769 by providing the required official documentation, while simultaneously aligning the board's LED semantics entirely with the PX4 standard.

Key Changes:

- Add complete corvon 743v1 hardware documentation and manufacturer link.

- Fix LED out-of-bounds bug and strictly align RGB states to Pixhawk standard (LED_BLUE=0, LED_RED=1, LED_GREEN=3).

- Update bootloader pin config (hw_config.h) to use red LED for boot/error, and update pre-built bootloader.bin.

* Prettier and file reduce

* docs: address reviewer feedback & board ID fix

* Apply suggestion from @hamishwillee

Co-authored-by: Hamish Willee <hamishwillee@gmail.com>

* docs: resolve final reviewer feedback (PPM, Debug Port, Manufacturer List)

---------

Co-authored-by: Hamish Willee <hamishwillee@gmail.com>
Co-authored-by: Ramon Roche <mrpollo@gmail.com>

docs/en/SUMMARY.md

@@ -164,6 +164,7 @@
       - [ARK Electronics ARKV6X](flight_controller/ark_v6x.md)
       - [ARK FPV Flight Controller](flight_controller/ark_fpv.md)
       - [ARK Pi6X Flow Flight Controller](flight_controller/ark_pi6x.md)
+      - [CORVON 743v1](flight_controller/corvon_743v1.md)
       - [CUAV Nora](flight_controller/cuav_nora.md)
       - [CUAV V5+ (FMUv5)](flight_controller/cuav_v5_plus.md)
         - [Wiring Quickstart](assembly/quick_start_cuav_v5_plus.md)

docs/en/flight_controller/autopilot_manufacturer_supported.md

@@ -18,6 +18,7 @@ The boards in this category are:
 - [ARK Electronics ARKV6X](../flight_controller/ark_v6x.md) (and [ARK Electronics Pixhawk Autopilot Bus Carrier](../flight_controller/ark_pab.md))
 - [ARK FPV Flight Controller](../flight_controller/ark_fpv.md)
 - [ARK Pi6X Flow Flight Controller](../flight_controller/ark_pi6x.md)
+- [CORVON 743v1](../flight_controller/corvon_743v1.md)
 - [CUAV Nora](../flight_controller/cuav_nora.md) (CUAV X7 variant)
 - [CUAV V5+](../flight_controller/cuav_v5_plus.md) (FMUv5)
 - [CUAV V5 nano](../flight_controller/cuav_v5_nano.md) (FMUv5)

docs/en/flight_controller/corvon_743v1.md

@@ -0,0 +1,109 @@
+# CORVON 743v1
+
+<Badge type="tip" text="PX4 v1.18" />
+
+:::warning
+PX4 does not manufacture this (or any) autopilot. Contact the manufacturer for hardware support or compliance issues.
+:::
+
+The _CORVON 743v1_ is a flight controller designed by Feikong Technology Co., Ltd under the CORVON brand.
+It features a powerful STM32H743 processor, dual high-performance IMUs (BMI088/BMI270), and an extensive array of interfaces.
+
+With its highly integrated 36x36mm footprint and 9g weight, and specialized interfaces like a direct plug-and-play DJI O3 Air Unit connector, this flight controller is optimized for space-constrained FPV builds and agile multirotors that require top-tier processing power and sensor redundancy.
+
+The board uses [Pixhawk Autopilot Standard Connections](https://docs.px4.io/main/en/flight_controller/autopilot_pixhawk_standard.html).
+
+<img src="../../assets/flight_controller/corvon_743v1/corvon_743v1_top.jpg" width="400px" title="CORVON 743v1 Top Baseboard" /> <img src="../../assets/flight_controller/corvon_743v1/corvon_743v1_bottom.jpg" width="400px" title="CORVON 743v1 Bottom Interfaces" />
+
+::: info
+This flight controller is [manufacturer supported](../flight_controller/autopilot_manufacturer_supported.md).
+:::
+## Key Features
+
+- **MCU:** STM32H743VIT6 MCU (32 Bit Arm® Cortex®-M7, 480MHz, 2MB Flash, 1MB RAM)
+- **IMU:** Bosch BMI088, BMI270 (Dual IMU redundancy)
+- **Barometer:** DPS310
+- **Magnetometer:** IST8310
+- **OSD:** Onboard AT7456E
+- **Interfaces:**
+  - 7x UARTs
+  - 1x CAN (UAVCAN)
+  - 1x I2C
+  - Dedicated RC Input (UART6)
+  - 10x PWM outputs (DShot & Bi-Directional DShot supported)
+  - Dedicated DJI O3 Air Unit connector
+- **Power:** 
+  - 9V 3A BEC
+  - 5V 3A BEC
+  - ADC for battery voltage (up to 6S) and current monitoring
+
+## Where to Buy
+
+Order from [CORVON](https://corvon.tech).
+
+## Physical / Mechanical
+
+- **Mounting:** 30.5 x 30.5mm, Φ4mm
+- **Dimensions:** 36 x 36 x 8 mm
+- **Weight:** 9g
+
+## Specifications
+
+### Processors & Sensors
+
+- **FMU Processor:** STM32H743
+  - 32 Bit Arm® Cortex®-M7, 480MHz
+  - 2MB Flash, 1MB RAM
+- **On-board Sensors:**
+  - Accel/Gyro: Bosch BMI088, BMI270
+  - Barometer: DPS310
+  - Compass: IST8310
+
+### Power Configuration
+
+The board has an internal voltage sensor and connections on the ESC connector for an external current sensor.
+- The voltage sensor handles up to 6S LiPo batteries.
+- Two onboard BECs provide robust peripheral power (9V 3A and 5V 3A).
+
+## Connectors & Pinouts
+
+The following image shows the port connection details, including RC, UARTs, CAN, I2C, SWD Debug, and VTX connections.
+
+<img src="../../assets/flight_controller/corvon_743v1/CORVON743V1_PortsConnection.png" width="800px" title="CORVON 743v1 Ports" />
+
+### Standard Serial Port Mapping
+
+| UART   | PX4 Target Config | Default Usage |
+| ------ | ----------------- | ------------- |
+| USART1 | TELEM1            | MAVLink       |
+| UART4  | TELEM2            | MAVLink       |
+| USART2 | GPS1              | GPS           |
+| USART3 | TELEM3            |               |
+| UART8  | URT6              |               |
+| USART6 | RC                | RC Input      |
+| UART7  | TELEM4            | ESC Telemetry |
+
+### Debug Port 
+
+The board features a **4-pin SWD Debug** interface located on the right side of the board. This includes `SWCLK`, `SWDIO`, `3V3`, and `GND` for full hardware debugging. While a dedicated UART isn't strictly reserved for the NSH console by default, the full-speed USB connection provides MAVLink Console access out of the box.
+
+### RC Input
+
+RC Input is mapped to **UART6** via the explicit `SBUS/CRSF` connector block. 
+- It fully supports PX4's standard `RC_INPUT` module protocols.
+- The connector exposes both `RX6` and `TX6`, which makes it fully capable of bidirectional receiver protocols such as TBS Crossfire (CRSF), ELRS, and FPort, as well as traditional single-wire standards like SBUS (which operates inverted on RX6). 
+
+## Building/Loading Firmware
+
+::: tip
+Most users will not need to build this firmware (from PX4 v1.18).
+It is pre-built and automatically installed by _QGroundControl_ when appropriate hardware is connected.
+:::
+
+To [build PX4](../dev_setup/building_px4.md) for this target from source:
+
+```sh
+make corvon_743v1_default
+```
+
+Initial firmware flashing can be done over USB via QGroundControl. The bootloader status aligns with standard generic PX4 LED indications (Red = Bootloader/Error, Blue = Active/Activity, Green = Powered).