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/coverart/provider.go

@@ -16,8 +16,7 @@ import (
 type Provider interface {
 	// ID is a stable lowercase token persisted in DB columns
 	// (cover_art_source / artist_art_source) and the
-	// cover_art_provider_settings.provider_id key, plus referenced
-	// in the operator-facing UI.
+	// cover_art_provider_settings.provider_id key, and shown in the admin UI.
 	ID() string
 
 	// DisplayName is the human-readable label shown in the admin
@@ -36,7 +35,7 @@ type Provider interface {
 	// with this provider on. Both v1 providers return true.
 	DefaultEnabled() bool
 
-	// Configure receives the operator's settings (api_key, enabled
+	// Configure receives the admin's settings (api_key, enabled
 	// flag) and applies them. Called at boot during reconciliation
 	// and on every admin PATCH. Implementations must be idempotent
 	// and goroutine-safe (the enricher may be reading concurrently).
@@ -84,7 +83,7 @@ type AlbumCoverProvider interface {
 
 // ReleaseGroupCoverProvider is an opt-in capability for sources that can
 // answer by MusicBrainz release group, which is how the release catalogue
-// names an album before any edition of it is held (M502 #5519).
+// names an album before any edition of it is held.
 type ReleaseGroupCoverProvider interface {
 	AlbumCoverProvider
 	FetchReleaseGroupCover(ctx context.Context, groupMBID string) ([]byte, error)