refactor(memory): extract sync + status helpers

src/memory/headers-fingerprint.ts

@@ -0,0 +1,16 @@
+function normalizeHeaderName(name: string): string {
+  return name.trim().toLowerCase();
+}
+
+export function fingerprintHeaderNames(headers: Record<string, string> | undefined): string[] {
+  if (!headers) return [];
+  const out: string[] = [];
+  for (const key of Object.keys(headers)) {
+    const normalized = normalizeHeaderName(key);
+    if (!normalized) continue;
+    out.push(normalized);
+  }
+  out.sort((a, b) => a.localeCompare(b));
+  return out;
+}
+