feat: finalize documentation and validation (Task 7)

- Rewrite project CLAUDE.md to match actual C/Unity implementation and modules
- Add docs/hardware_connection_diagram.md (ESP32-C6 <-> Ballu AC wiring)
- Add docs/home_assistant_integration.md (HA usage examples)
- Update Readme.md doc index and fix unclosed code fence
- Validate docs against implementation (build + all tests pass)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Readme.md

@@ -36,10 +36,22 @@ test/
   app_controller_test.c       - End-to-end integration tests (full command cycles)
 
 docs/
-  protocol.md                 - MideaUART protocol details
-  zcl_hvac.md                 - Zigbee ZCL Thermostat cluster details
-  Hardware integration guide.md - Hardware connection information
-  Build system details.md     - Build system and dependencies
+  protocol.md                    - MideaUART protocol details
+  zcl_hvac.md                    - Zigbee ZCL Thermostat cluster details
+  hardware_connection_diagram.md - ESP32-C6 <-> Ballu AC wiring diagram
+  home_assistant_integration.md  - Home Assistant usage examples
+  Hardware integration guide.md  - ESP32-C6 hardware integration (RU)
+  Build system details.md        - Build system and dependencies
+```
+
+## Documentation
+
+- [MideaUART protocol](docs/protocol.md)
+- [Zigbee ZCL Thermostat cluster](docs/zcl_hvac.md)
+- [Hardware connection diagram](docs/hardware_connection_diagram.md)
+- [Home Assistant integration guide](docs/home_assistant_integration.md)
+- [ESP32-C6 hardware integration guide](docs/Hardware%20integration%20guide.md)
+- [Build system details](docs/Build%20system%20details.md)
 
 ## Getting Started