fix: handle follower and shout notifications in notifications_seen_thread

- Add support for marking follower notifications as seen (thread='followers')
- Add support for marking new shout notifications as seen
- Use enum constants (NotificationAction, NotificationEntity) instead of strings
- Improve thread ID parsing to support different formats
- Remove obsolete TODO about notification_id offset
- Better error handling with logger.warning() instead of exceptions

Resolves TODOs on lines 253 and 286 in resolvers/notifier.py

resolvers/follower.py

@@ -50,10 +50,10 @@ def get_entity_field_name(entity_type: str) -> str:
         ValueError: Unknown entity_type: invalid
     """
     entity_field_mapping = {
-        "author": "following",     # AuthorFollower.following -> Author
-        "topic": "topic",          # TopicFollower.topic -> Topic
+        "author": "following",  # AuthorFollower.following -> Author
+        "topic": "topic",  # TopicFollower.topic -> Topic
         "community": "community",  # CommunityFollower.community -> Community
-        "shout": "shout"           # ShoutReactionsFollower.shout -> Shout
+        "shout": "shout",  # ShoutReactionsFollower.shout -> Shout
     }
     if entity_type not in entity_field_mapping:
         msg = f"Unknown entity_type: {entity_type}"