Go back to the hardlink deduplicator (1da0132), keeping backups

Restores the code of 1da0132 ("Add a setting to hide the quarantine from
Plex") and removes everything added after it: the tag editor, album art,
organizing/naming, the step-by-step tune-up and library types.

Kept:
- Database backups (Settings -> Backups): scheduled, manual, download,
  restore, and the optional backup before every action.
- The .env-driven docker-compose.yml for Arcane.

Databases that already ran the later migrations keep working: migrations
6-10 stay in the list (they only add columns) so numbering never goes
backwards, and Undo refuses History entries of removed features instead
of treating them as links.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/export.go

@@ -23,7 +23,6 @@ var kindLabels = map[string]string{
 	store.KindFuzzy:     "similar title",
 	store.KindElsewhere: "same top folder, other subfolder",
 	store.KindApprox:    "approximate match",
-	store.KindInode:     "same file, other path",
 	store.KindNone:      "no match",
 }