Fix relay not turning off after integration restart

On restart, pv_state resets to IDLE so the computed decision is always
  False on the first recalculate. Comparing against self.decision (also
  False) meant relay_control was never called, leaving the relay physically
  ON past the PV target and cut-off temperature limits.

  - Compare decision against the actual relay_on state instead of the
    coordinator's previous self.decision, so any discrepancy (including
    one left by a restart or an external integration) is corrected
    immediately on every recalculate.
  - Call _recalculate() at the end of async_setup() so the relay is synced
    on startup without waiting for an external state-change event.

  Co-Authored-By: Claude

custom_components/boiler_aux_heater_3phase/coordinator.py

@@ -174,6 +174,10 @@ class BoilerAuxHeaterCoordinator:
         # B4: Restore persisted boost state
         await self._async_restore_boost_state()
 
+        # Sync relay to current decision immediately, without waiting for a
+        # state change event (handles relay left ON before a restart).
+        self._recalculate()
+
     async def _async_restore_boost_state(self) -> None:
         """Restore bath boost state from storage after HA restart."""
         data = await self._store.async_load()
@@ -431,7 +435,6 @@ class BoilerAuxHeaterCoordinator:
         allowed = hp_aux_off and allow_usage and boiler_temp_ok
 
         # F1: Compute decision reason
-        old_decision = self.decision
         if manual_override:
             self.decision = True
             self.decision_reason = "Manual override"
@@ -463,7 +466,7 @@ class BoilerAuxHeaterCoordinator:
             self.decision = False
             self.decision_reason = "OFF: No heating demand"
 
-        if self.decision != old_decision:
+        if self.decision != relay_on:
             self.hass.async_create_task(self._async_control_relay(self.decision))
 
         self._notify_listeners()