fix: embedding migration, worker error handling, path traversal security, response mismatches (unread-count, plugins, manifests), frontend type safety

app/routes/notifications.py

@@ -67,7 +67,7 @@ async def mark_notification_read_endpoint(
     }
 
 
-@router.get("/unread-count", response_model=UnreadCountResponse)
+@router.get("/unread-count")
 async def unread_count_endpoint(
     db: AsyncSession = Depends(get_db),
     current_user: dict = Depends(require_permission("notifications:read")),
@@ -76,7 +76,7 @@ async def unread_count_endpoint(
     tenant_id = uuid.UUID(current_user["tenant_id"])
     user_id = uuid.UUID(current_user["user_id"])
     count = await get_unread_count(db, tenant_id, user_id)
-    return {"count": count}
+    return count
 
 
 @router.get("/types")