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/reacquisition/sweeper.go

@@ -15,8 +15,8 @@ import (
 )
 
 // Sweeper periodically wants back albums whose files have been missing past
-// the grace window (milestone #290, M502 #5520). Searching for them is the
-// search schedule's (#5521), which retries per want.
+// the grace window. Searching for them is the search schedule's, which
+// retries per want.
 //
 // Deliberately a periodic worker rather than a hook inside the scanner's
 // reconcile pass: reconcile runs inside a scan and re-runs often, and a
@@ -28,7 +28,7 @@ type Sweeper struct {
 	logger   *slog.Logger
 	tick     time.Duration
 	// releaseGroup names the MusicBrainz release group of a release id, for an
-	// album whose tags never carried one (#5241). Wants are kept by release
+	// album whose tags never carried one. Wants are kept by release
 	// group. A field so tests can stand in for MusicBrainz.
 	releaseGroup func(ctx context.Context, releaseMBID string) (string, error)
 }
@@ -79,7 +79,7 @@ func (s *Sweeper) SweepOnce(ctx context.Context) error {
 	q := dbq.New(s.pool)
 	var res PassResult
 	// Counted, not acted on: an album MusicBrainz cannot name is not a
-	// failure to retry, it is a permanent gap the operator should see.
+	// failure to retry, it is a permanent gap an admin should see.
 	if n, cerr := q.CountAlbumsMissingWithoutMbid(ctx); cerr == nil {
 		res.Unnameable = n
 	}