TempControllerBase: require PID gains via set_params(), not the constructor

Mirrors components/pid/pid.py's own Pid.set_params() pattern: params/
thresholds start out None, and set_params() configures pid_hold/pid_heat/
pid_cool from them. process()/process_fsm() fail naturally (TypeError on
None) if called before set_params() - same as Pid.process() already does -
rather than a new bespoke check. Updates all callers (server/brewpi.py,
SudForecastEstimator, and the pid/sud demo scripts) to call set_params()
right after construction.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DkkuG48uHFCGKe6dPSERFk

scripts/demos/pid/demo_temp_controller.py

@@ -43,7 +43,8 @@ if __name__ == '__main__':
 	temp_ist = 0
 	temp_soll = 20
 	heatrate_soll = 1.25
-	ctrl = TempController(dt, ctrl_params)
+	ctrl = TempController(dt)
+	ctrl.set_params(ctrl_params)
 	ctrl.set_enabled(True)
 	plant = Pot(dt)
 	plant.set_plant_params(plant_params)

scripts/demos/pid/demo_temp_controller_smith.py

@@ -43,7 +43,8 @@ if __name__ == '__main__':
 	temp_ist = 0
 	temp_soll = 20
 	heatrate_soll = 1.25
-	ctrl = TempController(dt, ctrl_params, plant_params, theta_amb)
+	ctrl = TempController(dt, plant_params, theta_amb)
+	ctrl.set_params(ctrl_params)
 	ctrl.set_enabled(True)
 	plant = Pot(dt)
 	plant.set_plant_params(plant_params)

scripts/demos/sud/demo_sud.py

@@ -48,7 +48,8 @@ if __name__ == '__main__':
 		"Td"		: 60
 	}
 
-	ctrl = TempController(dt, ctrl_params, plant_params, theta_amb)
+	ctrl = TempController(dt, plant_params, theta_amb)
+	ctrl.set_params(ctrl_params)
 	plant = Pot(dt)
 	plant.set_plant_params(plant_params)
 	plant.set_ambient_temperature(theta_amb)