refactor: improve authentication and user data handling

- Replace user cache queries with direct database queries to ensure data consistency
- Fix token_type parameter in verify_token calls (access token verification)
- Fix role-based permission check using dictionary ranking instead of string comparison
- Fix logout operation to use correct JWT claim name (user_id instead of sub)
- Simplify user authentication flow by removing unnecessary cache layer
- Optimize session initialization in main.py using create_session helper
- Remove unused imports and exception variables

src/api/announcements/routes.py

@@ -142,7 +142,7 @@ class AnnouncementOptionalAuthAdapter(ApiAdapter):
 
         token = authorization.replace("Bearer ", "").strip()
         try:
-            payload = await AuthService.verify_token(token)
+            payload = await AuthService.verify_token(token, token_type="access")
             user_id = payload.get("user_id")
             if not user_id:
                 return None