Add CRM stub flag, deploy/backup scripts, CI and prod runbook

- CRM_USE_STUB: local runs no longer reach the live CRM. With only the
  Checkbox stub, a stub receipt would still move the real order to PACKED.
  Refused in production, same as CHECKBOX_USE_STUB.
- scripts/deploy.sh: backup, fast-forward main, build, health check and
  code rollback on failure. scripts/backup.sh: pg_dump with verification
  and 14-day rotation (used by cron and deploy.sh).
- Gitea Actions CI: ruff + pytest, oxlint + build.
- DEPLOY.md runbook; CLAUDE.md rules for safe local development.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/app/services/crm/client.py

@@ -2,8 +2,10 @@
 
 from __future__ import annotations
 
+from functools import lru_cache
 from typing import Protocol
 
+from app.core.config import settings
 from app.schemas.orders import OrderOut
 
 
@@ -15,3 +17,18 @@ class CrmClient(Protocol):
     async def get_orders(self, *, status: str) -> list[OrderOut]: ...
 
     async def set_status(self, *, order_id: str, status: str) -> None: ...
+
+
+@lru_cache
+def get_crm_client() -> CrmClient:
+    """Один экземпляр на процесс: стаб копит выставленные статусы в памяти."""
+    if settings.crm_use_stub:
+        if settings.is_production:
+            raise RuntimeError("CRM_USE_STUB=true заборонено в production")
+        from app.services.crm.stub_client import StubCrmClient
+
+        return StubCrmClient()
+
+    from app.services.crm.exo_client import ExoCrmClient
+
+    return ExoCrmClient(settings)