- Fixed room name mismatch: ProgressService was broadcasting to
'download_progress' but JS clients join 'downloads' room
- Added _get_room_for_progress_type() mapping function
- Updated all progress methods to use correct room names
- Added 13 new tests for room name mapping and broadcast verification
- Updated existing tests to expect correct room names
- Fixed JS clients to join valid rooms (downloads, queue, scan)
- Added optional 'key' and 'folder' fields to ProgressUpdate dataclass
- key: Primary series identifier (provider key, e.g., 'attack-on-titan')
- folder: Optional series folder name for display (e.g., 'Attack on Titan (2013)')
- Updated start_progress() and update_progress() methods to accept key/folder parameters
- Enhanced to_dict() serialization to include key/folder when present
- Updated all docstrings to clarify identifier usage
- Added 5 new comprehensive unit tests for key/folder functionality
- All 25 ProgressService tests passing
- Updated infrastructure.md with series identifier documentation
- Maintains backward compatibility - fields are optional
- Completed Phase 3, Task 3.3 of identifier standardization initiative
