Remove the unused tc_trace logging

trace_tc (tasks/tracer.py's TracerTask wired to a generic Tracer instance)
was logging to tc_trace.mat, but its var_list was empty, so it only ever
wrote a bare tick counter - no actual tc data, despite the name. Drop the
dead plumbing and the now-unused tracer.py module entirely; the real,
populated brewpi.mat logging (sensor/heater/tc data, built directly inside
TracerTask) is untouched.

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

server/brewpi.py

@@ -14,7 +14,6 @@ from components.actor import HeaterFactory, StirrerFactory
 from components.sud import Sud
 from components.sud_forecast import SudForecastEstimator
 from tasks import TaskManager, TempSensorTask, HeaterTask, PotTask, TcTask, StirrerTask, TracerTask, SudTask, SudLogTask
-from tracer import Tracer
 
 import argparse as ap
 
@@ -92,10 +91,6 @@ if __name__ == '__main__':
 	tc_task = TcTask(tc, DT_TASK, dispatcher.msgio_get("TempCtrl"))
 	taskmgr.add(tc_task)
 
-	tc_trace_vars = []
-
-	trace_tc = Tracer(tc, tc_trace_vars, name='tc_trace')
-
 	# Stirrer
 	stirrer = StirrerFactory.create(config['Controller']['stirrer_name'], DT, config['Stirrer'])
 	stirrer_task = StirrerTask(stirrer, DT_TASK, dispatcher.msgio_get("Stirrer"))
@@ -117,7 +112,7 @@ if __name__ == '__main__':
 	taskmgr.add(SudLogTask(sud, tc, heater, heater_task, sud_task, DT_TASK))
 
 	# Tracer
-	taskmgr.add(TracerTask(sensor, heater, tc, trace_tc, DT_TASK_TRACER, dispatcher.msgio_get("Tracer")))
+	taskmgr.add(TracerTask(sensor, heater, tc, DT_TASK_TRACER, dispatcher.msgio_get("Tracer")))
 
 	# Assign data flow
 	# Assign tc control value to heater