Support Speed Fan as valve-like output

[chrisob]

I'd like to use this to control a speed fan. Tested in my own HA (sensor & target are humidity values here):

2025-02-12 23:53:07.563 DEBUG (MainThread) [custom_components.smart_thermostat.climate] climate.tent_pid_humidity_exhaust: Received new temperature: 58.55
2025-02-12 23:53:07.563 INFO (MainThread) [custom_components.smart_thermostat.climate] climate.tent_pid_humidity_exhaust: Obtained temperature 58.55 with set point 50.0. Activating SmartThermostat.
2025-02-12 23:53:07.563 DEBUG (MainThread) [custom_components.smart_thermostat.climate] climate.tent_pid_humidity_exhaust: New PID control output: -100 (error = -8.55, dt = 0.00, p=-85.50, i=-40.30, d=0.00, e=0.00)
2025-02-12 23:53:07.563 INFO (MainThread) [custom_components.smart_thermostat.climate] climate.tent_pid_humidity_exhaust: Change state of fan.tent_controller_fan to 100