chore: import DH V2 D5.6.4 production baseline

api-v3/src/inspection-closing/canonical-json.ts

@@ -0,0 +1,22 @@
+import { createHash } from 'node:crypto';
+
+function canonicalValue(value: unknown): unknown {
+  if (value instanceof Date) return value.toISOString();
+  if (Array.isArray(value)) return value.map(canonicalValue);
+  if (value !== null && typeof value === 'object') {
+    return Object.fromEntries(
+      Object.entries(value as Record<string, unknown>)
+        .sort(([left], [right]) => left.localeCompare(right))
+        .map(([key, item]) => [key, canonicalValue(item)]),
+    );
+  }
+  return value;
+}
+
+export function canonicalJson(value: unknown): string {
+  return JSON.stringify(canonicalValue(value));
+}
+
+export function sha256CanonicalJson(value: unknown): string {
+  return createHash('sha256').update(canonicalJson(value)).digest('hex');
+}