feat: implement Gitea notification polling and state persistence

Squash merged Gitea notification polling and state persistence.

core/queue.py

@@ -1,6 +1,6 @@
 import logging
 from pydantic import BaseModel
-from typing import Any
+from typing import Any, Optional
 from gitea.models import IssueModel, PullRequestModel
 
 logger: logging.Logger = logging.getLogger("work-queue")
@@ -11,6 +11,7 @@ class WorkItem(BaseModel):
     task_type: str  # 'issue' or 'pr'
     task_number: int
     task_info: IssueModel | PullRequestModel
+    notification_id: Optional[int] = None
     priority: int = 0