feat(customers): 发送/接收列改今日口径(对齐云客;本地消息表Asia/Shanghai今日聚合)

- CustomerOut 加 send_today/receive_today(路由赋值,非ORM列)
- /api/customers 每页一次 GROUP BY(owner IN 走复合索引前缀)
- 前端列优先今日值,无消息数据回退原raw字段;列名对齐云客「发送条数/接收条数」
- TDD:今日3发2收+昨日不计入+无消息客户0

Co-Authored-By: Claude <noreply@anthropic.com>

yunkes/src/api/types.ts

@@ -30,6 +30,9 @@ export interface Customer {
   head_image_url?: string | null
   /** ms-epoch of most recent message */
   last_chat_time?: number | null
+  /** 今日发送/接收条数(本地消息聚合,对齐云客今日口径)。 */
+  send_today?: number | null
+  receive_today?: number | null
   /** ms epoch of friend add time (from raw_json.addTime). */
   add_time?: number | null
   message_count?: number | null