Five update_match endpoints hardcoded the provider as 'spotify' when
saving manual fixes to the discovery cache, but the re-discovery worker
queries the cache with _get_active_discovery_source() — the user's
actual primary. If the primary was Deezer/iTunes/Discogs/Hydrabase, the
provider column never matched, so every manual fix looked like it
vanished on restart.
Replaced 'spotify' with _get_active_discovery_source() at all 5 sites:
- Tidal update_match (web_server.py:34569)
- Deezer update_match (web_server.py:36235)
- Spotify Public update_match (web_server.py:37084)
- YouTube update_match (web_server.py:38037)
- Discovery Pool fix (web_server.py:49787)
Now symmetric with how the auto-discovery workers already save. Spotify-
primary users see no change (the hardcoded value matched their source).
Version bumped to 2.38 with changelog + version-info entries.
6ceedc8fd4
