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/album_loudness.go

@@ -12,7 +12,7 @@ import (
 	syncpkg "git.fabledsword.com/bvandeusen/minstrel/internal/sync"
 )
 
-// Album loudness (M464 #4996).
+// Album loudness.
 //
 // Album-mode normalization plays a whole album at one gain, so the quiet
 // interlude stays quieter than the single it sits between. That gain comes
@@ -168,7 +168,7 @@ func (w *LoudnessBackfillWorker) storeAlbumLoudness(
 		return fmt.Errorf("read inputs: %w", err)
 	}
 	a := computeAlbumLoudness(inputs)
-	// Logged before the write, for the reason storeLoudness gives (#2704). A
+	// Logged before the write, for the reason storeLoudness gives. A
 	// failed log stores nothing, so the digest still differs and the next
 	// pass tries again.
 	if albumVisibleChange(before, a) {