继续收紧 TypeScript：ClaimIdentity 契约与 flow 出口类型

- 新增 types/claim-identity，统一 ClaimIdentity / Payload / AdminSummary
- 导出 KuaishouCloudFlow、KuaishouFeifeiFlow 作为 normalize 出口
- 生产路径 JsonObject 统一从 types/json 导入，去掉 rebind as any
- 前后端 claimIdentity 类型字段对齐

apps/backend/src/services/fulfillment/kuaishou-cloud/index.ts

@@ -14,6 +14,10 @@ export {
   isSameKuaishouCloudRoleIdentity,
   resolveKuaishouCloudBindUrlExpiresAt,
 } from './domain.js'
+export type {
+  KuaishouCloudDeliveryItem,
+  KuaishouCloudFlow,
+} from './domain.js'
 export { resolvePersistedCloudtentaclesContextBySourceKeys } from './cloudtentacles-context.js'
 export { ensureTaskClaimLink } from './ensure-claim-link.js'
 export {