feat: 添加土壤和光照阈值控制，优化状态上报逻辑

README.md

@@ -95,7 +95,11 @@ idf.py -p /dev/ttyACM0 flash monitor
   "lux": "40",
   "pump": "on",
   "light": "off",
-  "mode": "auto"
+  "mode": "auto",
+  "soil_on": 35.0,
+  "soil_off": 45.0,
+  "light_on": 100.0,
+  "light_off": 350.0
 }
 ```
 
@@ -103,6 +107,10 @@ idf.py -p /dev/ttyACM0 flash monitor
 - `pump`：`on/off`
 - `light`：`on/off`
 - `mode`：`auto/manual`
+- `soil_on`：土壤湿度低阈值（低于该值自动开泵）
+- `soil_off`：土壤湿度高阈值（高于该值自动关泵）
+- `light_on`：光照低阈值（低于该值自动开灯）
+- `light_off`：光照高阈值（高于该值自动关灯）
 
 ### WEX -> ESP32