Add Checkbox ETTN receipts for Nova Poshta COD waybills

Cashier creates an ETTN receipt in Checkbox bound to the TTN with payment
control; Checkbox fiscalizes it itself when the parcel is paid for.

- cash_registers (Fernet-encrypted license key / PIN) and receipts tables
- Checkbox HTTP client + stub (ETTN does not work on test registers)
- two-phase create via ARQ job, timeout reconciliation, cron status polling
- /receipts and /cash-registers API, audit records
- dashboard: per-order and bulk create, prepayment, cancel; cash registers page

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

backend/app/api/v1/receipts.py

@@ -0,0 +1,87 @@
+"""ЕТТН-чеки Checkbox: запрос создания (массово), просмотр, отмена."""
+
+from __future__ import annotations
+
+import uuid
+
+from fastapi import APIRouter, Depends, HTTPException, Request, status
+from sqlalchemy import select
+
+from app.api.deps import (
+    CashierUser,
+    CheckboxClientDep,
+    SessionDep,
+    TaskQueueDep,
+    require_any,
+)
+from app.db.models.receipt import Receipt
+from app.schemas.receipts import ReceiptCreateRequest, ReceiptCreateResponse, ReceiptOut
+from app.services import receipts as receipts_service
+from app.services.checkbox.client import CheckboxError
+
+router = APIRouter(prefix="/receipts", tags=["receipts"], dependencies=[Depends(require_any)])
+
+
+@router.post("", response_model=ReceiptCreateResponse, status_code=status.HTTP_202_ACCEPTED)
+async def create_receipts(
+    payload: ReceiptCreateRequest,
+    request: Request,
+    session: SessionDep,
+    queue: TaskQueueDep,
+    actor: CashierUser,
+) -> ReceiptCreateResponse:
+    result = await receipts_service.request_receipts(
+        session,
+        [(item.order_id, item.prepayment_kopecks) for item in payload.items],
+        user=actor,
+        request=request,
+    )
+    await session.commit()
+
+    # После commit: worker должен увидеть строку `pending`.
+    for receipt in result.created:
+        await queue.enqueue("create_ettn_receipt", str(receipt.id))
+
+    return ReceiptCreateResponse(
+        created=[ReceiptOut.from_receipt(receipt) for receipt in result.created],
+        errors=result.errors,
+    )
+
+
+@router.get("", response_model=list[ReceiptOut])
+async def list_receipts(session: SessionDep, order_id: str | None = None) -> list[ReceiptOut]:
+    query = select(Receipt).order_by(Receipt.created_at.desc()).limit(500)
+    if order_id is not None:
+        query = query.where(Receipt.order_id == order_id)
+    return [ReceiptOut.from_receipt(receipt) for receipt in await session.scalars(query)]
+
+
+@router.get("/{receipt_id}", response_model=ReceiptOut)
+async def get_receipt(receipt_id: uuid.UUID, session: SessionDep) -> ReceiptOut:
+    receipt = await session.get(Receipt, receipt_id)
+    if receipt is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Чек не найден")
+    return ReceiptOut.from_receipt(receipt)
+
+
+@router.post("/{receipt_id}/cancel", response_model=ReceiptOut)
+async def cancel_receipt(
+    receipt_id: uuid.UUID,
+    request: Request,
+    session: SessionDep,
+    checkbox: CheckboxClientDep,
+    actor: CashierUser,
+) -> ReceiptOut:
+    try:
+        receipt = await receipts_service.cancel_receipt(
+            session, checkbox, receipt_id, user=actor, request=request
+        )
+    except receipts_service.ReceiptStateError as exc:
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail=str(exc)) from exc
+    except CheckboxError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_502_BAD_GATEWAY, detail=f"Checkbox: {exc}"
+        ) from exc
+    if receipt is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Чек не найден")
+    return ReceiptOut.from_receipt(receipt)