Track hidden changes behind redaction

internal/engine/diff_snapshot.go

@@ -12,6 +12,7 @@ type pairedDiffSnapshot struct {
 	leftRedacted     bool
 	rightRedacted    bool
 	requiresFallback bool
+	hiddenChanged    bool
 }
 
 func preparePairedDiffSnapshot(left, right *document.Node, path Path, sensitivity *diffSensitivity) (pairedDiffSnapshot, bool) {
@@ -24,6 +25,7 @@ func preparePairedDiffSnapshot(left, right *document.Node, path Path, sensitivit
 		right:         redactedDiffNode(right),
 		leftRedacted:  left != nil,
 		rightRedacted: right != nil,
+		hiddenChanged: true,
 	}, true
 }
 
@@ -37,6 +39,7 @@ func preparePairedDiffNodes(left, right *document.Node, path Path, sensitivity *
 			right:         redactedDiffNode(right),
 			leftRedacted:  left != nil,
 			rightRedacted: right != nil,
+			hiddenChanged: !configurationValuesEqual(left, right),
 		}, true
 	}
 	if left != nil && right != nil && left.Kind != right.Kind {
@@ -121,6 +124,7 @@ func preparePairedDiffMapping(left, right *document.Node, path Path, sensitivity
 		}
 		redacted.leftRedacted = redacted.leftRedacted || child.leftRedacted
 		redacted.rightRedacted = redacted.rightRedacted || child.rightRedacted
+		redacted.hiddenChanged = redacted.hiddenChanged || child.hiddenChanged
 	}
 	redacted.left = leftCopy
 	redacted.right = rightCopy
@@ -170,6 +174,7 @@ func preparePairedDiffSequence(left, right *document.Node, path Path, sensitivit
 		}
 		result.leftRedacted = result.leftRedacted || child.leftRedacted
 		result.rightRedacted = result.rightRedacted || child.rightRedacted
+		result.hiddenChanged = result.hiddenChanged || child.hiddenChanged
 	}
 	return result, true
 }