[SENSOR] Build occupancy sensor with drift simulation

[ezehf2]

Create occupancy_sensor.py extending the sensor base class. Occupancy values should be whole numbers between 0 and the room's maximum capacity. Simulate gradual change — people arriving and leaving in small numbers rather than jumping between extremes. The room capacity should be passed in as a parameter when the sensor is created so it works for different room sizes. Include a short manual test printing five consecutive readings.