Make notification data column a string

src/db/models/notification.py

@@ -1,5 +1,5 @@
 from datetime import UTC, datetime
-from typing import Annotated, Any, ClassVar, Literal, final
+from typing import Annotated, ClassVar, Literal, final
 
 from beanie import Document, Indexed
 from pydantic import Field
@@ -15,7 +15,7 @@ class Notification(Document):
     user: Annotated[BeanieLink[User], Indexed()]
     event_type: Annotated[Literal["reminder", "invitation"], Indexed()]
     message: str
-    data: Any
+    data: str
     read: bool
     created_at: datetime = Field(default_factory=lambda: datetime.now(UTC))
     read_at: datetime | None = None