Add CRM order queue: live sync, view modal, receipt tabs, delete

Wires the CRM (exoCRM GetOrders) into the dashboard as a locally
persisted order queue instead of the previous static mockup:

- CrmClient Protocol + ExoCrmClient/StubCrmClient for the CRM's
  signed JSON-RPC API
- Order model + migration, synced from CRM on each queue view;
  soft-deleted orders stay hidden across re-syncs
- GET/DELETE /api/v1/orders with "no receipt"/"receipt issued" tabs
  (the latter is empty until Checkbox fiscalization lands)
- Dashboard: real order list, item-detail modal, tab switcher,
  one-click delete

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.env.example

@@ -48,3 +48,11 @@ REFRESH_TOKEN_EXPIRE_DAYS=7
 FIRST_ADMIN_EMAIL=admin@example.com
 FIRST_ADMIN_PASSWORD=change-me-admin-password
 FIRST_ADMIN_NAME=Администратор
+
+# --- CRM (exoCRM) ---------------------------------------------------------
+# Ключи доступа к магазину — запросить у администратора CRM.
+CRM_BASE_URL=https://optstore.exocrm.com/api/1.1/
+CRM_API_KEY=change-me-crm-apikey
+CRM_SECRET_KEY=change-me-crm-secretkey
+CRM_SHOP_KEY=change-me-crm-shopkey
+CRM_SID=1