fix(lfx): reset factory-registered flag on ServiceManager teardown

teardown() emptied self.factories but left factory_registered set, so
get_service()'s lazy re-registration was skipped and later lookups raised
NoFactoryRegisteredError. Once Graph.arun started routing through the
executor service, that surfaced as intermittent flow-execution 500s in the
backend unit suite whenever a sibling test had torn the global manager down.

src/lfx/src/lfx/services/manager.py

@@ -306,6 +306,12 @@ class ServiceManager:
 
         self.services = {}
         self.factories = {}
+        # ``teardown`` empties the factory registry, so the "registered" flag has
+        # to drop too: get_service() re-registers factories only when
+        # are_factories_registered() is False. Leaving it set after a teardown
+        # makes the next lookup skip re-registration and raise
+        # NoFactoryRegisteredError.
+        self.factory_registered = False
 
     @classmethod
     def get_factories(cls) -> list[ServiceFactory]:

src/lfx/tests/unit/services/test_service_manager.py

@@ -359,6 +359,27 @@ class TestTeardown:
         # Services should be cleared
         assert ServiceType.STORAGE_SERVICE not in service_manager.services
 
+    @pytest.mark.asyncio
+    async def test_teardown_clears_factories_registered_flag(self, service_manager):
+        """teardown() must clear the factories-registered flag, not just the dict.
+
+        get_service() (both lfx and langflow) re-registers factories only when
+        are_factories_registered() returns False. teardown() empties
+        self.factories, so if it leaves the flag set, every later lookup skips
+        re-registration and raises NoFactoryRegisteredError. That surfaced as
+        flow-execution 500s once Graph.arun routed through the executor service
+        and a sibling test had torn the global manager down.
+        """
+        service_manager.register_service_class(ServiceType.STORAGE_SERVICE, LocalStorageService)
+        service_manager.get(ServiceType.STORAGE_SERVICE)
+        service_manager.set_factory_registered()
+        assert service_manager.are_factories_registered() is True
+
+        await service_manager.teardown()
+
+        assert service_manager.factories == {}
+        assert service_manager.are_factories_registered() is False
+
 
 class TestConfigDirectorySource:
     """Tests for config_dir parameter with real services."""