feat: schedule periodic reports asynchronously

ai_knowledge_base_v2/apps/backend/app/main.py

@@ -12,6 +12,7 @@ from app.core.exception_handlers import register_exception_handlers
 from app.core.observability import RequestObservabilityMiddleware, configure_logging
 from app.services.secret_service import SecretService
 from app.services.maintenance_service import MaintenanceService
+from app.services.periodic_report_worker import PeriodicReportWorker
 import asyncio
 
 
@@ -22,14 +23,17 @@ async def lifespan(app: FastAPI):
     if settings.auto_create_tables:
         create_tables()
     maintenance_task = asyncio.create_task(MaintenanceService.run_forever())
+    periodic_report_task = asyncio.create_task(PeriodicReportWorker.run_forever())
     try:
         yield
     finally:
-        maintenance_task.cancel()
-        try:
-            await maintenance_task
-        except asyncio.CancelledError:
-            pass
+        for task in (maintenance_task, periodic_report_task):
+            task.cancel()
+        for task in (maintenance_task, periodic_report_task):
+            try:
+                await task
+            except asyncio.CancelledError:
+                pass
 
 
 settings = get_settings()