Pot.__init__ now only takes dt; set_plant_params() and set_ambient_temperature() must be called before process(), which now raises RuntimeError if either is missing instead of silently computing on whatever the constructor happened to default to. set_ambient_temperature() only seeds the plant's starting temperature the first time it's called, so changing ambient mid-run still can't clobber an in-progress simulated temperature. Updates all callers (server/brewpi.py, TempController(Smith)'s two internal models, SudForecastEstimator, and the plant/pid/sud demo scripts) to call the setters right after construction. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01DkkuG48uHFCGKe6dPSERFk