feat: Implement Zigbee stack and ZCL Thermostat cluster (Task 3)

docs/plans/2026-07-05-ballu-ac-esp32c6-controller-implementation.md

@@ -42,14 +42,14 @@ Implementation of ESP32-C6 based AC controller that bridges Zigbee (Home Assista
 - [x] Update Readme.md
 
 ### Task 3: Zigbee Stack and ZCL Thermostat Cluster
-- [ ] Initialize Zigbee stack on ESP32-C6
-- [ ] Implement ZCL Thermostat cluster server
-- [ ] Handle local_temperature attribute reporting
-- [ ] Implement system_mode attribute handling (Cool/Heat/Auto/Off)
-- [ ] Add weekly schedule command handling (set/clear/get)
-- [ ] Write unit tests for ZCL attribute processing
-- [ ] Run tests - must pass before next task
-- [ ] Update Readme.md
+- [x] Initialize Zigbee stack on ESP32-C6
+- [x] Implement ZCL Thermostat cluster server
+- [x] Handle local_temperature attribute reporting
+- [x] Implement system_mode attribute handling (Cool/Heat/Auto/Off)
+- [x] Add weekly schedule command handling (set/clear/get)
+- [x] Write unit tests for ZCL attribute processing
+- [x] Run tests - must pass before next task
+- [x] Update Readme.md
 
 ### Task 4: Zigbee-UART Integration Layer
 - [ ] Create message broker between Zigbee and UART layers
@@ -143,4 +143,4 @@ typedef struct {
 
 **External system updates**:
 - Home Assistant configuration examples
-- ESP-IDF project configuration and dependencies
+- ESP-IDF project configuration and dependencies