feat(01-01): lib/api/index.ts 末尾追加凭据槽位具名 re-export

- 在 handleApiError 之后追加 7 行具名 re-export 块
- 暴露 4 个公共符号：getCredentialSlot / updateCredentialSlot / CredentialSlot / CredentialSlotUpdatePayload
- 路径相对 './credential-slot'，与现有 export * from './card' 等风格在同文件混用合法
- 现有 export */usersApi/rolesApi/handleApiError 完全不变

qy-lty-admin/lib/api/index.ts

@@ -194,3 +194,11 @@ export const handleApiError = (error: any) => {
   }
   return "发生未知错误，请重试"
 }
+
+// 凭据槽位（Milestone v1.0 通用凭据槽位前端集成 — Phase 1 / CRED-FE-01）
+export {
+  getCredentialSlot,
+  updateCredentialSlot,
+  type CredentialSlot,
+  type CredentialSlotUpdatePayload,
+} from './credential-slot'