docs: server comments say what the code does, not how it came to be (#6277)

Comment blocks in cmd/minstrel and 30 smaller internal packages, rewritten
to rule 32's standard with each citation read in context: task, milestone
and rule ids go, and so do the stories they were attached to ("used to",
"Before #N", measurements from one install, quotes, pointers to Fabled
Librarian's records and to docs/superpowers files that are not in the
repo). Where a story wrapped a real constraint, the constraint stays as a
present-tense fact.

Comments that had gone stale are corrected:
- taste.Config: the tuned values are overlaid by internal/recsettings;
  it is no longer "a later follow-up".
- StorageConfig: the data dir holds art, caches and the stream secret,
  not only playlist covers.
- the Subsonic album list and getUser comments describe what they do
  today rather than a milestone that would change it.

Checked: the non-comment token stream of every changed file matches
HEAD, and gofmt -l is empty.

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

internal/subsonic/browse.go

@@ -26,8 +26,8 @@ type browseHandlers struct {
 // for backwards compatibility with clients that regroup client-side.
 const ignoredArticles = "The El La Los Las Le Les"
 
-// getMusicFolders always returns a single folder. Minstrel has no multi-library
-// concept in M1; clients use the folder id as an opaque cookie so we return 1.
+// getMusicFolders always returns a single folder: Minstrel serves one library,
+// and clients use the folder id as an opaque cookie, so it is 1.
 func (b *browseHandlers) getMusicFolders(w http.ResponseWriter, r *http.Request) {
 	Write(w, r, MusicFoldersResponse{
 		Envelope: NewEnvelope("ok"),
@@ -236,9 +236,8 @@ func (b *browseHandlers) getSong(w http.ResponseWriter, r *http.Request) {
 }
 
 // getAlbumList2 returns a paged album list filtered by type. Supported types
-// match the Subsonic spec § getAlbumList2. "recent"/"frequent" require play
-// history (M2) and currently return an empty list rather than an error so
-// clients that poll them don't break.
+// match the Subsonic spec § getAlbumList2. "recent" and "frequent" return an
+// empty list rather than an error, so clients that poll them don't break.
 func (b *browseHandlers) getAlbumList2(w http.ResponseWriter, r *http.Request) {
 	params := r.URL.Query()
 	listType := params.Get("type")
@@ -285,15 +284,14 @@ func (b *browseHandlers) getAlbumList2(w http.ResponseWriter, r *http.Request) {
 			WriteFail(w, r, ErrMissingParameter, "Missing required parameter: genre")
 			return
 		}
-		// Genre is a plain string as of #367 — the query now splits
-		// tracks.genre on [;,] instead of comparing the whole column, so a
-		// client asking for "Rock" also reaches tracks tagged "Rock;Pop".
-		// Previously those were unreachable from either of their genres.
+		// The query splits tracks.genre on [;,] rather than comparing the
+		// whole column, so a client asking for "Rock" also reaches tracks
+		// tagged "Rock;Pop".
 		albums, err = q.ListAlbumsByGenre(r.Context(), dbq.ListAlbumsByGenreParams{
 			Genre: genre, Lim: int32(size), Off: int32(offset),
 		})
 	case "recent", "frequent":
-		// Play history lands in M2; return empty to keep clients happy.
+		// Not served from play history: empty keeps clients working.
 		albums = nil
 	default:
 		WriteFail(w, r, ErrGeneric, "Invalid list type: "+listType)

internal/subsonic/replaygain_test.go

@@ -11,7 +11,7 @@ import (
 )
 
 // OpenSubsonic's replayGain is an object in JSON and an element with
-// attributes in XML. Clients parse both, so both are pinned (#4997).
+// attributes in XML. Clients parse both, so both are pinned.
 func TestSongRef_ReplayGainEncodesForBothFormats(t *testing.T) {
 	gain, peak := float32(-4.5), float32(0.8913)
 	tr := dbq.Track{Title: "Song", FilePath: "/m/a.flac", FileFormat: "flac"}

internal/subsonic/star.go

@@ -40,7 +40,7 @@ func (m *mediaHandlers) handleStar(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if trackID.Valid {
-		// Stars the song: every copy of it (M498 #5438).
+		// Stars the song: every copy of it.
 		liked, err := q.LikeTrack(r.Context(), dbq.LikeTrackParams{UserID: user.ID, TrackID: trackID})
 		if err != nil {
 			WriteFail(w, r, ErrGeneric, "Could not star track")
@@ -182,7 +182,7 @@ func (m *mediaHandlers) handleGetStarred2(w http.ResponseWriter, r *http.Request
 // loadStarred fetches the user's full starred set in liked_at DESC order,
 // projects to Subsonic refs (Song / Album / Artist).
 func loadStarred(ctx context.Context, q *dbq.Queries, userID pgtype.UUID) ([]SongRef, []AlbumRef, []ArtistRef, error) {
-	const cap = 500 // bounded for safety; M2 doesn't paginate getStarred
+	const cap = 500 // bounded for safety; getStarred is not paginated
 	songs := []SongRef{}
 	albums := []AlbumRef{}
 	artists := []ArtistRef{}

internal/subsonic/types.go

@@ -181,7 +181,7 @@ type SongRef struct {
 	BitRate     int      `json:"bitRate,omitempty" xml:"bitRate,attr,omitempty"`
 	IsDir       bool     `json:"isDir" xml:"isDir,attr"`
 	Type        string   `json:"type" xml:"type,attr"`
-	// ReplayGain is OpenSubsonic's replayGain (M464 #4997): Minstrel's own
+	// ReplayGain is OpenSubsonic's replayGain: Minstrel's own
 	// measurements, so third-party clients that level by ReplayGain do it
 	// from the same numbers the Minstrel apps use. Omitted until measured.
 	ReplayGain *ReplayGain `json:"replayGain,omitempty" xml:"replayGain,omitempty"`

internal/subsonic/user.go

@@ -52,9 +52,8 @@ func handleGetUser(w http.ResponseWriter, r *http.Request) {
 		WriteFail(w, r, ErrNotAuthorized, "Not authorized to view other users")
 		return
 	}
-	// We don't have a per-user lookup wired up yet; until then admins asking
-	// for another username see the caller's roles. Acceptable while M1 has a
-	// single user; revisit once user management lands.
+	// No per-user lookup: an admin asking for another username is answered
+	// with the caller's own roles.
 	Write(w, r, UserResponse{
 		Envelope: NewEnvelope("ok"),
 		User:     userPayload(caller),