Description of Change

This pull request introduces support for setting default (initial) measurement values for various Zigbee sensor endpoint classes, ensuring that sensors start with a defined value after a factory reset and before receiving actual readings. The changes include newsetDefaultValue methods for several sensor types, updates to documentation, and adjustments to example usage to demonstrate the new functionality.

Core feature: Default value support for Zigbee sensors

• AddedsetDefaultValue methods to the following sensor classes, allowing users to set an initial measurement value to be used after a factory reset and before the sensor reports real data:
  • ZigbeeTempSensor,ZigbeeCarbonDioxideSensor,ZigbeeFlowSensor,ZigbeeIlluminanceSensor,ZigbeePM25Sensor,ZigbeePressureSensor, andZigbeeWindSpeedSensor (libraries/Zigbee/src/ep/ZigbeeTempSensor.cpp,ZigbeeCarbonDioxideSensor.cpp,ZigbeeFlowSensor.cpp,ZigbeeIlluminanceSensor.cpp,ZigbeePM25Sensor.cpp,ZigbeePressureSensor.cpp,ZigbeeWindSpeedSensor.cpp; corresponding.h files)[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]

Documentation updates

• Updated documentation for all affected sensor endpoint types to describe the newsetDefaultValue method, its usage, and its effect during factory reset (before commissioning or joining a network) (docs/en/zigbee/ep_temperature_sensor.rst,ep_carbon_dioxide_sensor.rst,ep_flow_sensor.rst,ep_illuminance_sensor.rst,ep_pm25_sensor.rst,ep_pressure_sensor.rst,ep_wind_speed_sensor.rst)[1][2][3][4][5][6][7]

Example usage improvements

• Updated example sketches to demonstrate setting a default value for temperature and humidity sensors, including changes to theaddHumiditySensor method to accept a default value parameter (libraries/Zigbee/examples/Zigbee_Temp_Hum_Sensor_Sleepy/Zigbee_Temp_Hum_Sensor_Sleepy.ino,Zigbee_Temperature_Sensor.ino,ZigbeeTempSensor.cpp)[1][2][3]

These changes make it easier to ensure predictable sensor behavior after a factory reset and improve the clarity and usability of the sensor API.

Test Scenarios

Tested using the Temperature sensor example and HomeAssitant (ZHA)

Related links

Closes#12041