A manually-fixed mirrored track silently reverted to 'Wing It' after re-running
discovery. Two compounding causes:
- extra_data is MERGED on save (update_mirrored_track_extra_data), and the
manual-fix DB write (web_server.py) didn't clear the prior wing_it_fallback
flag — so a track fixed after being a Wing It stub kept wing_it_fallback=True.
- the Playlist Pipeline pre-scan checked wing_it_fallback BEFORE manual_match
(if/elif), so the stale flag won: the track was re-discovered and, on a miss,
fell back to Wing It — discarding the user's pick.
Fix: extracted the pre-scan gate into core.discovery.manual_match.should_rediscover
(manual_match checked FIRST = authoritative, regardless of leftover flags), and
the manual-fix write now also clears wing_it_fallback/unmatched_by_user. Behavior
is identical for every other branch — only the manual-vs-wing-it ordering changes.
Tested at the seam incl. the exact regression (wing_it_fallback + manual_match
both set -> skip). 227 discovery tests green.
c20150e370