Album completeness and any other repair job now uses the centralized source/client helpers instead of a worker-local Spotify client or override plumbing
- This keeps source selection aligned with the configured primary provider and removes the last Spotify-only special case from the job path.
This change ultimately is a step towards further centralizing the Spotify client access and the associated `is_spotify_authenticated` check.
- Currently these look-ups are done all over the place in different feature implementations directly, but moving forward, any feature that uses `get_primary_client` or `get_client_for_source` to access the Spotify client, won't have to duplicate any rate-limiting or auth checks as long as these getters are used
8a1ae00946