feat: Z38 grant Yuheng agents ready-to-use access

Complete permissions during every bind and token path, expose effective access in the console, and keep the platform return path globally available.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/数据同步-开通说明.md

@@ -59,7 +59,7 @@ postgres://user:pass@127.0.0.1:5432/app_online?sslmode=disable
 - `POST /api/v1/auth/token` → `channel_id` / `online_db_id` / `database_name` / `sync_bound`
 - `GET /api/v1/agents/me`（智能体 Bearer）
 - `POST /api/v1/auth/yuheng/ticket-exchange`（仅宇恒 HMAC 凭票）
-- `POST /api/v1/auth/yuheng/restore-by-host`（Z34b：按宇恒 `host_key` 恢复已有同步绑定，票内 phone 可空）
+- `POST /api/v1/auth/yuheng/restore-by-host`（按宇恒 `host_key` 恢复已有绑定并自动补齐建站权限；票内 phone 可空）
 
 ## 运维高级：手建通道（过渡 / 多机）