Both controllers had nearly identical process_fsm(), process_pid(),
and all getters/setters; only Kalman/model setup and process()
genuinely differed, and the duplication had already drifted (the
Smith variant resets model state on entering HEAT, the plain one
didn't).
Add TempControllerBase with the shared logic and three small hooks
(init_kalman, on_state_entered, post_pid) subclasses use to plug in
their own Kalman/model behavior. Each subclass now contains only what
makes it different.
Also fixes a latent crash: TempController's constructor only accepted
(dt, params), but PidFactory/brewpi.py always call it with a third
model_params arg, so pid_type "Normal" would have raised TypeError.
The shared base's model_params=None default fixes this. Also
initializes the Smith controller's trace attributes in __init__
instead of leaving them undefined until the first process() call.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
