Chats: show which order a provider writes about, or that there is no order

- Provider messages store the order that was current when they wrote: a started
  order first, otherwise the nearest assigned one within -4h..+12h; none — "no order".
- Admin chat: order tag above each provider message, "now / next" order strip in
  the conversation header, order number (or "no order") in the thread list.
- Telegram notification to the team gets an order line or "no current order".
- Test for the order-picking rule; demo shows both cases.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

packages/i18n/locales/zh.json

@@ -869,7 +869,9 @@
       "channelSupport": "客服",
       "channelConcierge": "礼宾",
       "file": "文件",
-      "chatAssigned": "{{by}} 将对话转交给你：{{name}}"
+      "chatAssigned": "{{by}} 将对话转交给你：{{name}}",
+      "order": "订单 #{{number}}",
+      "noOrder": "当前没有订单"
     },
     "partner": {
       "valid": "{{name}} — {{level}}，会员卡有效",