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/recsettings/service_test.go

@@ -282,7 +282,7 @@ func TestUpdate_NoOpWritesNoAudit(t *testing.T) {
 	}
 }
 
-// --- Discover scope (#2377, milestone #268 slice 6) ---
+// --- Discover scope ---
 
 func TestNew_SeedsDiscoverDefaults(t *testing.T) {
 	pool := newPool(t)
@@ -310,9 +310,8 @@ func TestUpdateDiscover_PersistsAndAudits(t *testing.T) {
 		t.Errorf("SnoozeDays = %v, want 30", got)
 	}
 
-	// The audit row must land under the new scope. This is the assertion that
-	// would have caught a missing rule-#36 CHECK migration: without expanding
-	// recommendation_tuning_audit's whitelist, this INSERT fails at runtime.
+	// The audit row must land under the new scope: a scope missing from
+	// recommendation_tuning_audit's CHECK fails this INSERT at runtime.
 	rows := auditRows(t, pool)
 	if len(rows) != 1 {
 		t.Fatalf("audit rows = %d, want 1", len(rows))
@@ -343,8 +342,7 @@ func TestUpdateDiscover_Validation(t *testing.T) {
 		{"weight past the typo bound", map[string]float64{"tag_overlap_weight": 100}},
 		// A sub-day snooze isn't a snooze, it's a flicker.
 		{"snooze under a day", map[string]float64{"snooze_days": 0.5}},
-		// Past a year it's a permanent dismissal wearing a snooze's clothes —
-		// the shape rule #101 rules out.
+		// Past a year it's a permanent dismissal wearing a snooze's clothes.
 		{"snooze past a year", map[string]float64{"snooze_days": 400}},
 	}
 	for _, c := range cases {
@@ -360,9 +358,8 @@ func TestUpdateDiscover_Validation(t *testing.T) {
 	}
 }
 
-// Weight 0 must be accepted — it's the operator's off switch for the whole
-// tag term, so a "must be positive" bound would remove their ability to
-// disable the feature.
+// Weight 0 must be accepted: it's the off switch for the whole tag term, so
+// a "must be positive" bound would leave no way to disable it.
 func TestUpdateDiscover_ZeroWeightIsAllowed(t *testing.T) {
 	pool := newPool(t)
 	s := newService(t, pool)