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/auth/clientip_test.go

@@ -68,8 +68,8 @@ func TestClientIP(t *testing.T) {
 			want:       "198.51.100.7",
 		},
 		{
-			// A client prepending a lie is only reachable if the operator
-			// over-counts their proxies; at the correct depth it's skipped.
+			// A client prepending a lie is only reachable if the hops are
+			// over-counted; at the correct depth it's skipped.
 			name:       "forged prefix is not reached at the correct depth",
 			hops:       1,
 			remoteAddr: "172.18.0.1:40000",
@@ -178,7 +178,7 @@ func TestIsHTTPS(t *testing.T) {
 		tls   bool
 		want  bool
 	}{
-		// The three cases rule 94 names.
+		// No trusted proxy, a trusted proxy saying https, and one saying http.
 		{name: "hops 0 ignores a forwarded https", hops: 0, proto: "https", want: false},
 		{name: "hops 1 believes a forwarded https", hops: 1, proto: "https", want: true},
 		{name: "plain request is not https", hops: 1, want: false},