M8-T10: add WarmteLink serial worker manager

app/main.py

@@ -38,6 +38,7 @@ from app.services.modbus_poll import poll_all_enabled_devices, BASE_POLL_TICK_SE
 from app.services.ha_discovery import publish_discovery, publish_states
 from app.services.tibber_prices import refresh_prices
 from app.services.energy_cost import compute_closed_periods
+from app.services.warmtelink_worker import warmtelink_worker_manager
 from app.services.timezone import local_tz
 from scripts.app_db_adopt import AppDatabaseAdoptionError, validate_app_runtime_db
 
@@ -273,18 +274,28 @@ async def lifespan(_: FastAPI):
         _startup_runtime_settings = build_runtime_settings(_startup_session, get_settings())
     finally:
         _startup_session.close()
-    mqtt_manager.connect(_startup_runtime_settings)
+    serial_started = False
+    try:
+        mqtt_manager.connect(_startup_runtime_settings)
 
-    # DSMR sources carry their own runtime configuration and are reconciled
-    # after the MQTT manager is connected.
-    apply_dsmr_subscription()
+        # DSMR sources carry their own runtime configuration and are reconciled
+        # after the MQTT manager is connected.
+        apply_dsmr_subscription()
+        # Mark it before reconcile: a partial reconcile can already own a fd or
+        # a non-daemon thread and must receive the same orderly shutdown.
+        serial_started = True
+        warmtelink_worker_manager.start()
 
-    yield
-
-    # MQTT: clean shutdown before the process exits.
-    mqtt_manager.disconnect()
-
-    scheduler.shutdown(wait=False)
+        yield
+    finally:
+        # Serial descriptors/workers must be handled first on every exit path.
+        if serial_started:
+            try:
+                warmtelink_worker_manager.shutdown()
+            except Exception:
+                logger.exception("WarmteLink shutdown failed")
+        mqtt_manager.disconnect()
+        scheduler.shutdown(wait=False)
 
 
 def create_app() -> FastAPI: