feat: a held album below the quality you settle for, or holding a video rip, stays wanted for a better copy, and the import replaces the old tracks with their likes and plays carried over (M502 #5524)

- acquisition_settings.upgrade_until (default High quality lossy, Lidarr's
  cutoff, note #5527; "" is off), an "Upgrade until" row under Searching.
- The wanted worker judges held albums hourly: tier per format from size per
  second (the scanner records no bitrate), the album's worst. Below the
  cutoff it is wanted for quality; a video rip among its tracks always.
- The schedule searches upgrades weekly, after open wants; a release no
  better than the copy held is refused ("not_better").
- The import matches each file to the track it would replace (recording,
  then disc/track) and replaces it when it is a rip or the file is a better
  tier: over the same path in one rename, or filed beside it and the old
  track folded in (library.ReplaceTrack: file first, then foldTrackInto).
  Nothing better: the release is set aside.
- Collection › Upgrades (Lidarr's Cutoff Unmet); Suspect sources says when a
  clean copy was looked for instead of Lidarr's search.

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

internal/api/admin_search.go

@@ -43,6 +43,9 @@ type searchSettingsView struct {
 	SeedRatio  float32 `json:"seed_ratio"`
 	SeedDays   int32   `json:"seed_days"`
 	StallHours int32   `json:"stall_hours"`
+	// UpgradeUntil is the tier a held album is upgraded to (#5524); "" is
+	// no quality upgrades.
+	UpgradeUntil string `json:"upgrade_until"`
 }
 
 func searchSettings(s dbq.AcquisitionSetting, roots []string) searchSettingsView {
@@ -51,6 +54,7 @@ func searchSettings(s dbq.AcquisitionSetting, roots []string) searchSettingsView
 		AllowedQualities: s.AllowedQualities, Tiers: release.Tiers, LastPass: s.LastPass,
 		ImportRoot: s.ImportRoot, ScanPaths: roots,
 		SeedRatio: s.SeedRatio, SeedDays: s.SeedDays, StallHours: s.StallHours,
+		UpgradeUntil: s.UpgradeUntil,
 	}
 	if v.ScanPaths == nil {
 		v.ScanPaths = []string{}
@@ -86,6 +90,7 @@ type putSearchSettingsBody struct {
 	SeedRatio           float32  `json:"seed_ratio"`
 	SeedDays            int32    `json:"seed_days"`
 	StallHours          int32    `json:"stall_hours"`
+	UpgradeUntil        string   `json:"upgrade_until"`
 }
 
 // handlePutSearchSettings implements PUT /api/admin/acquisition/settings.
@@ -108,6 +113,10 @@ func (h *handlers) handlePutSearchSettings(w http.ResponseWriter, r *http.Reques
 			return
 		}
 	}
+	if body.UpgradeUntil != "" && !release.KnownTier(body.UpgradeUntil) {
+		writeErr(w, apierror.BadRequest("bad_upgrade_until", "unknown quality "+body.UpgradeUntil))
+		return
+	}
 	if body.ImportRoot != "" && !slices.Contains(h.importer.Roots, body.ImportRoot) {
 		writeErr(w, apierror.BadRequest("bad_import_root", "file new music into one of the library's folders"))
 		return
@@ -121,6 +130,7 @@ func (h *handlers) handlePutSearchSettings(w http.ResponseWriter, r *http.Reques
 	s, err := dbq.New(h.pool).UpdateAcquisitionSettings(r.Context(), dbq.UpdateAcquisitionSettingsParams{
 		AutoGrab: body.AutoGrab, SearchIntervalHours: body.SearchIntervalHours, AllowedQualities: body.AllowedQualities,
 		ImportRoot: body.ImportRoot, SeedRatio: body.SeedRatio, SeedDays: body.SeedDays, StallHours: body.StallHours,
+		UpgradeUntil: body.UpgradeUntil,
 	})
 	if err != nil {
 		writeErrWithLog(w, h.logger, "admin search settings: put", apierror.Internal(err))
@@ -322,7 +332,7 @@ func (h *handlers) writeSearchErr(w http.ResponseWriter, err error) bool {
 	case errors.Is(err, pgx.ErrNoRows):
 		writeErr(w, apierror.NotFound("want"))
 	case errors.Is(err, wanted.ErrWantHeld):
-		writeErr(w, apierror.Conflict("want_held", "the library already holds this album"))
+		writeErr(w, apierror.Conflict("want_held", "the library already holds this album, and it isn't wanted for a better copy"))
 	default:
 		writeErrWithLog(w, h.logger, "admin wanted: search", apierror.Internal(err))
 	}