Option2 무결성 강화: integrity index 추가, 인덱스 정렬/교차 검증, referencedAt 매트릭스, README 문서화 (TDD)

components/BuilderClientPage.tsx

@@ -9,6 +9,7 @@ import { buildZip } from '@/lib/exporter/zip'
 import { buildExtrasForPage } from '@/lib/exporter/extras'
 import { buildAssetsMetadata } from '@/lib/exporter/assets.meta'
 import { buildAssetsIndex } from '@/lib/exporter/assets.index'
+import { buildAssetsIntegrityIndex } from '@/lib/exporter/assets.integrity.index'
 import type { Section } from '@/lib/state/store'
 import { createFormStore, type FormState } from '@/lib/state/formStore'
 import FormBuilderPanel from '@/components/FormBuilderPanel'
@@ -285,7 +286,11 @@ export default function BuilderClientPage() {
     const baseExtras = buildExtrasForPage(valid, { robotsText: robotsTextOverride, manifest: manifestOverride, sheetsMode })
     const extras: Record<string, Uint8Array> = {
       ...baseExtras,
-      ...(am ? { 'assets.json': buildAssetsMetadata(am), 'assets.index.json': buildAssetsIndex(am) } : {}),
+      ...(am ? {
+        'assets.json': buildAssetsMetadata(am),
+        'assets.index.json': buildAssetsIndex(am),
+        'assets.integrity.index.json': buildAssetsIntegrityIndex(am),
+      } : {}),
     }
     const zipBytes = await buildZip({ html: exported.html, css: exported.css, js: exported.js, assets, extras })
     download('landing.zip', zipBytes)