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/netsettings/service.go

@@ -1,6 +1,6 @@
 // Package netsettings holds the DB-backed network settings the request path
-// needs. Today that's the trusted reverse-proxy depth used to pull a real
-// client address out of X-Forwarded-For (#2453).
+// needs: the trusted reverse-proxy depth used to pull a real client address
+// out of X-Forwarded-For, and the public address links are built from.
 //
 // Values are cached under an RWMutex and refreshed on write. That isn't an
 // optimisation: auth.ClientIP runs in the RequireUser middleware for every
@@ -53,7 +53,7 @@ type Service struct {
 // It ALWAYS returns a usable Service, even alongside a non-nil error. The
 // value it holds sits on the authenticated request path, so a boot-time
 // database hiccup must degrade to the default rather than take every request
-// down with it (rule #131). The error is returned so the caller can log that
+// down with it. The error is returned so the caller can log that
 // the cache holds a default rather than stored state.
 func New(ctx context.Context, pool *pgxpool.Pool, logger *slog.Logger) (*Service, error) {
 	s := &Service{pool: pool, logger: logger, hops: DefaultTrustedProxyHops}
@@ -84,7 +84,7 @@ func (s *Service) Hops() int {
 }
 
 // SetHops persists a new depth and refreshes the cache, so an admin change
-// takes effect on the next request with no restart (rule #25).
+// takes effect on the next request with no restart.
 func (s *Service) SetHops(ctx context.Context, hops int) error {
 	// Range first, availability second. The argument is wrong regardless of
 	// whether the database is reachable, and the distinction is user-visible:
@@ -115,7 +115,7 @@ func (s *Service) SetHops(ctx context.Context, hops int) error {
 	return nil
 }
 
-// PublicURL returns the operator-set address users reach Minstrel at, with no
+// PublicURL returns the admin-set address users reach Minstrel at, with no
 // trailing slash, or "" when it hasn't been set. Links that leave the app (a
 // password-reset email) are built from this and never from the request's
 // Host header, which the requester controls. Nil-safe like Hops.