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/db/prisma/migrations/20261021140000_chat_message_order/migration.sql

@@ -0,0 +1,6 @@
+-- AlterTable
+ALTER TABLE "ConciergeMessage" ADD COLUMN     "orderId" TEXT;
+
+-- AddForeignKey
+ALTER TABLE "ConciergeMessage" ADD CONSTRAINT "ConciergeMessage_orderId_fkey" FOREIGN KEY ("orderId") REFERENCES "Order"("id") ON DELETE SET NULL ON UPDATE CASCADE;
+