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/importer/place.go

@@ -92,7 +92,19 @@ var taggable = map[string]bool{".flac": true, ".ogg": true, ".opus": true, ".mp3
 // container will not take the file's streams) the file is copied as it is
 // and tagged reports false. An existing dst is never overwritten.
 func Place(ctx context.Context, src, dst string, t Tags) (tagged bool, err error) {
-	if _, err := os.Lstat(dst); err == nil {
+	return placeFile(ctx, src, dst, t, false)
+}
+
+// Overwrite is Place onto a file an upgrade replaces (#5524): the new copy
+// takes the old one's path in one rename, so the library never sees the
+// path empty, and the track row at that path, history and all, carries on
+// with the new file.
+func Overwrite(ctx context.Context, src, dst string, t Tags) (tagged bool, err error) {
+	return placeFile(ctx, src, dst, t, true)
+}
+
+func placeFile(ctx context.Context, src, dst string, t Tags, overwrite bool) (tagged bool, err error) {
+	if _, err := os.Lstat(dst); err == nil && !overwrite {
 		return false, fmt.Errorf("%w: %s", ErrOccupied, dst)
 	}
 	dir := filepath.Dir(dst)
@@ -114,7 +126,7 @@ func Place(ctx context.Context, src, dst string, t Tags) (tagged bool, err error
 	if err := os.Chmod(tmp, 0o644); err != nil {
 		return false, fmt.Errorf("chmod %s: %w", tmp, err)
 	}
-	if _, err := os.Lstat(dst); err == nil {
+	if _, err := os.Lstat(dst); err == nil && !overwrite {
 		return false, fmt.Errorf("%w: %s", ErrOccupied, dst)
 	}
 	if err := os.Rename(tmp, dst); err != nil {