Add set_ambient_temperature and set_model_plant_params stubs to TempControllerBase

Same pattern as set_model_power: these methods only existed on the Smith
controller, forcing five hasattr guards at call sites. No-op stubs on the
base class give all controllers a stable interface; Smith overrides them.
Remove the now-redundant hasattr guards.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Tqxrk8uj4M3w3d3eXm3xK8

components/pid/temp_controller_base.py

@@ -89,6 +89,12 @@ class TempControllerBase(APid):
 	def post_pid(self):
 		pass
 
+	def set_ambient_temperature(self, theta_amb):
+		pass
+
+	def set_model_plant_params(self, model_params):
+		pass
+
 	def set_model_power(self, power):
 		pass