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)