docs: library comments say what the scanner and resolver do, not how they came to be (#6277)

Rewrites the internal/library comment blocks to rule 32. Task, milestone,
decision and rule ids are gone; the incidents behind them are restated as
the constraint they left (why a file is deleted before its row, why the
missing mark is a mark, why duplicates block on duration). Counts and
album names from one library are dropped from production comments; test
comments keep the names their fixtures use. The tagReadVersion log keeps
each version's before and after, without the measurements.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/library/song_link_test.go

@@ -151,7 +151,7 @@ func TestCrossReleaseCopiesCountAsOneSong_Integration(t *testing.T) {
 	}
 }
 
-// Without the operator's permission the resolver links nothing.
+// With auto-resolve off the resolver links nothing.
 func TestCrossReleaseLinkNeedsAutoResolve_Integration(t *testing.T) {
 	pool := newPool(t)
 	ctx := context.Background()
@@ -222,7 +222,7 @@ func songKeys(t *testing.T, q *dbq.Queries, ids ...pgtype.UUID) []pgtype.UUID {
 }
 
 // A cross-release group whose album holds the song twice (Humanz: Saturnz
-// Barz as a FLAC and a YouTube mp3, beside the single, #5401): the album's
+// Barz as a FLAC and a YouTube mp3, beside the single): the album's
 // extra copy is merged into its FLAC, the single stays, and the two copies
 // left are linked as one song.
 func TestResolveDuplicates_FoldsAnAlbumsExtraCopyInACrossReleaseGroup_Integration(t *testing.T) {