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/reconcile_test.go

@@ -26,7 +26,7 @@ type fakeReconciler struct {
 	listErr  error
 	markErr  error
 	clearErr error
-	// Change rows the reconcile pass asked the delta sync to emit (#2704).
+	// Change rows the reconcile pass asked the delta sync to emit.
 	loggedChanges []dbq.InsertLibraryChangesParams
 }
 
@@ -186,8 +186,8 @@ func TestReconcileMissing_DoesNotRemarkAlreadyMissingRows(t *testing.T) {
 }
 
 // The guard that matters most. A half-attached mount makes the walk succeed
-// while seeing only part of the library — evidence indistinguishable from a mass
-// deletion, so reconcile must refuse rather than guess.
+// while seeing only part of the library — evidence indistinguishable from a
+// mass deletion, so reconcile must refuse rather than guess.
 func TestReconcileMissing_RefusesWhenTooMuchWouldBeMarked(t *testing.T) {
 	root := populatedRoot(t)
 	s := testScanner(t, root)
@@ -288,8 +288,8 @@ func TestReconcileMissing_RefusesWhenRootEmpty(t *testing.T) {
 	}
 }
 
-// Several roots, one detached. Marking must not proceed on partial evidence just
-// because the other roots looked fine.
+// Several roots, one detached. Marking must not proceed on partial evidence
+// just because the other roots looked fine.
 func TestReconcileMissing_RefusesWhenAnyRootMissing(t *testing.T) {
 	good := populatedRoot(t)
 	s := testScanner(t, good, filepath.Join(t.TempDir(), "detached"))
@@ -336,8 +336,8 @@ func TestVerifyRootsPresent_NoRootsConfigured(t *testing.T) {
 
 // Without a change row the mark is invisible to every client:
 // /api/library/sync is a change-log feed, so a plain UPDATE never reaches
-// anyone. This was the gap that made #2704's wire field inert — the flag
-// existed and nothing ever told a client to re-read the track.
+// anyone, and the wire field would exist with nothing ever telling a client to
+// re-read the track.
 func TestReconcileMissing_MarkingEmitsSyncChanges(t *testing.T) {
 	s := testScanner(t, populatedRoot(t))
 
@@ -366,8 +366,8 @@ func TestReconcileMissing_MarkingEmitsSyncChanges(t *testing.T) {
 		t.Errorf("entity_type = %q, want track", got.EntityType)
 	}
 	// Upsert, not delete: the track still exists and keeps its history. A
-	// delete would tell clients to drop the row, which is the behaviour
-	// #2704 deliberately rejected.
+	// delete would tell clients to drop the row, and a missing file is
+	// expected to come back.
 	if got.Op != "upsert" {
 		t.Errorf("op = %q, want upsert — the row survives, only its state changed", got.Op)
 	}