feat: 이미지 최적화 옵션 추가(fetchpriority/srcset/sizes) (TDD)

- ExportOptions에 이미지 옵션 추가
- hero 이미지에 조건부 속성 렌더링
- 테스트: image.responsive.options.test.ts
- 전체 테스트 그린 유지

README.md

@@ -108,6 +108,20 @@ Usage:
 - Verify file size matches `entries[].size`.
 - Verify bundle integrity by recomputing `bundleHash` from sorted entries; useful for quick tamper detection.
 
+Example (Node):
+
+```ts
+import { verifyIntegrity } from '@/lib/exporter/verify'
+
+// extras must include 'assets.integrity.index.json', assets is a map of zipPath -> bytes
+const result = verifyIntegrity(extras, assets)
+if (!result.ok) {
+  console.error('Integrity check failed:', result.errors)
+}
+console.log('Summary:', result.summary)
+// { total, missing, integrityMismatches, sizeMismatches, bundleHashMismatch }
+```
+
 ### Google Sheets template (optional)
 
 - When included, ZIP contains: