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/acoustid/client.go

@@ -1,13 +1,13 @@
 // Package acoustid looks up MusicBrainz recording ids by acoustic fingerprint
-// through the AcoustID web service (M401).
+// through the AcoustID web service.
 //
-// What it relies on, from https://acoustid.org/webservice (read 2026-10-06):
+// What it relies on, from https://acoustid.org/webservice:
 //   - POST https://api.acoustid.org/v2/lookup with client, duration (whole
 //     seconds), fingerprint (fpcalc's compressed string) and meta. A gzip body
 //     with Content-Encoding: gzip is accepted and preferred, because
 //     fingerprints are long.
 //   - meta=recordings returns each recording's title, duration and artists,
-//     which the worker needs to tell several candidates apart (M401 D5).
+//     which the worker needs to tell several candidates apart.
 //   - "Do not make more than 3 requests per second."
 //   - The service is free for non-commercial use only.
 //
@@ -39,8 +39,7 @@ const (
 	// minInterval keeps to AcoustID's 3 requests a second with headroom: one
 	// every 400ms is 2.5 a second.
 	minInterval = 400 * time.Millisecond
-	// lookupTimeout bounds one request, connection included (rule 156). A
-	// lookup answers in well under a second; 20s is the line past which slow
+	// lookupTimeout bounds one request, connection included. A lookup answers in well under a second; 20s is the line past which slow
 	// has become never.
 	lookupTimeout = 20 * time.Second
 	// bodyLimit caps the response read. A lookup with meta=recordings for a
@@ -59,7 +58,7 @@ const (
 )
 
 var (
-	// ErrInvalidKey: the operator's application key was refused. No lookup
+	// ErrInvalidKey: the configured application key was refused. No lookup
 	// can succeed until it is changed, so the worker stops and says so.
 	ErrInvalidKey = errors.New("acoustid: the API key was refused")
 	// ErrInvalidFingerprint: AcoustID rejected this track's fingerprint. A