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/notifications/notifier_db_test.go

@@ -146,9 +146,9 @@ func TestNotify_CoalescedCountAddsUpWhileUnread_AndStartsAfreshOnceRead(t *testi
 	require.True(t, rows[1].ReadAt.Valid)
 }
 
-// M542: an update says more, newest names first, without arriving again. A
-// moved created_at was announced again on the phone, and a cleared emailed_at
-// was emailed again.
+// An update says more, newest names first, without arriving again: a moved
+// created_at would announce it again on the phone, and a cleared emailed_at
+// would email it again.
 func TestNotify_ACoalescedUpdateMergesNamesAndKeepsItsArrival(t *testing.T) {
 	pool := testPool(t)
 	q := dbq.New(pool)
@@ -238,9 +238,9 @@ func TestMarkRead_ScopedToTheOwner_AndIdempotent(t *testing.T) {
 	require.Zero(t, unread)
 }
 
-// Every kind the code knows must pass both CHECKs in the real schema. This is
-// rule 36's guard: a kind added in Go without the migration fails here, not in
-// production at INSERT time.
+// Every kind the code knows must pass both CHECKs in the real schema: a kind
+// added in Go without its migration fails here, not in production at INSERT
+// time.
 func TestEveryKindPassesTheSchemaChecks(t *testing.T) {
 	pool := testPool(t)
 	q := dbq.New(pool)