Across all background workers (Spotify/Tidal/Deezer/Qobuz/iTunes/
Discogs/Genius/AudioDB/MusicBrainz/Last.fm/SoulID + the metadata-update
worker) and the repair-job scanners. All converted to
`logger.debug("...: %s", e)`.
Two `_e` renames in genius_worker and soulid_worker where outer scope
was already binding `e`. Two finally-block sites in repair_jobs/
library_reorganize.py left silent (conn.close on shutdown path).
Refs #369
Class body byte-identical to original. The shared metadata_update_state
dict is bound at import time via init() so the class body can mutate
it without web_server.py rebinding.
web_server.py: 39754 → 39122 (-632 lines).
