Replace Robokassa with YooKassa as the RUB direct-rail provider. The wallet
model is untouched: one `direct` segment, the same spend wall, the same
per-channel merchant shops (D42) and `shop` on the order (D44).
The two providers are not shaped alike, and that drives the change:
- Opening a purchase is now an outbound API call (`POST /v3/payments`,
single-stage capture, redirect confirmation). The order id is both the
`Idempotence-Key` and `metadata.order_id`, so a retried create cannot mint a
second payment and a notification always resolves to its order.
- YooKassa does NOT sign notifications, so the body is never evidence: it only
names a payment, which is re-read with `GET /v3/payments/{id}`, and only that
answer is acted on. Two guards ride on it — the payment's metadata must name
the order, and its `test` flag must match the shop's, so a test-shop payment
can never credit real chips. The sender address is checked against YooKassa's
published ranges first, which stops a forger turning each fabricated
notification into an outbound call of ours.
- A notification lost for good would leave the money taken and the chips unowed,
silently. The existing pending-order reaper now asks the provider about each
order that reached its expiry age carrying a payment id, and credits the ones
really paid — one request per order over its whole life, not polling.
- `payment.canceled` records a `failed` event, so a declined payment is finally
surfaced to the customer as PAYMENTS.md §9 already specified.
- The admin refund moves the money through `POST /v3/refunds` before recording
anything; a failed call records nothing, so the ledger cannot claim a refund
that did not happen, and the recorded id is the provider's own.
- YooKassa has no cabinet-side generic receipt: «Чеки от ЮKassa» registers one
only if the request carries it, so every payment and refund now sends an
itemized `receipt` to the D36 confirmed email. The VAT rate code is a deploy
variable; the settlement subject and method are constants.
Robokassa is retired, not deleted: the direct rail falls back to it when no
YooKassa shop is configured and no deployment sets its credentials, so reviving
it is a credentials change rather than a code change. Its variables are removed
from compose, .env.example, write-prod-env.sh and the three workflows, and
recorded in backend/internal/robokassa/README.md together with the cabinet
configuration and the revival steps. Ledger rows keep `provider = 'robokassa'`;
that literal is load-bearing for the idempotency index.
No migration and no wire change: `orders.provider_payment_id` already existed,
and the client is rail-agnostic.
Decisions D47-D51 (revising D41) and stage E12 are baked into the docs.
Add the payment-intake write path (provider-agnostic) and the Robokassa
direct-rail glue, both unit-tested; transport, wire and UI follow.
- payments: extend the ledger insert to thread order_id/provider/
provider_payment_id (spend/grant pass nil); add the order store
(create/read/expire + a pack-price loader) and the fund credit — a
fund ledger row + a guarded balance upsert + mark-paid in one tx,
idempotent on the (provider, provider_payment_id) unique index, cache
invalidated after commit. A valid callback is honoured even on an
expired order. Service CreateOrder/Fund/ExpireOrders; Money.Major for
the provider amount field.
- robokassa: build the signed hosted-payment URL (SHA-256, order id via
Shp_order, InvId unused) and verify the Result callback signature
(Password2), extracting the order and amount. Receipt/fiscalisation is
configured shop-side, so no Receipt parameter is sent.
Ilia Denisov