Extract the storage layer into core

tests/test_timezones.py

@@ -38,7 +38,7 @@ def _make_hass_mock():
 
 
 async def _prepare(path):
-    database = NestQuestDatabase(_make_hass_mock())
+    database = NestQuestDatabase(_make_hass_mock().async_add_executor_job)
     await database.open(path)
     await apply_migrations(database)
     return database
@@ -313,7 +313,7 @@ def test_definition_business_regeneration_uses_pinned_today_not_host(
     business operations must regenerate against the pinned date and keep
     that first local day, proving the threaded ``today`` wins.
     """
-    import custom_components.nestquest.dao_instances as dao_instances_module
+    import core.dao_instances as dao_instances_module
 
     pinned = datetime.date(2026, 1, 14)
     host_today = datetime.date(2026, 1, 15)