- Add rollback on exception to prevent dirty database state
- Fix block verification threshold from >=1 to >=80%
- Remove technical 'failed' language from user messages
- Add empty content validation with warning
- Add NotionKBSyncService for immediate KB updates after page changes
- Implement block ID verification to ensure content freshness
- Refactor duplicate block processing logic to shared utils
- Add user-friendly status messages
- Include debug logging for troubleshooting