K1: card purchases on the server (schema 4, Enable Banking adapter, E-36 to E-44)

Contract (SPEC §14.8): migration 0004_card_purchases.sql (server schema 4, byte-identical
contract and server copies), E-36 to E-44 in contracts/openapi.yaml with the four new error
codes and a 502 response, examples for every card body and error code, the
match_card_purchase vectors (17 cases) with their Python reference in tools/contracts-check.py
(157 checks), web/src/api/schema.d.ts regenerated; web/src/lib/vectors.test.ts lists
match_card_purchase as not ported until K3 ports it (orchestrator's allowance).

Server: src/cards/ with the provider registry (CP-1), the CardSource trait and its
Enable Banking adapter (JWT RS256 kid = application id, /aspsps, /auth, /sessions,
transactions with PSU headers for user-present fetches, CP-14 error mapping, CP-7 mapping),
the windowed fetch (30-day windows newest first, split at the 100-row cap down to a day,
de-duplication by provider_ref, continuation keys, WRONG_TRANSACTIONS_PERIOD ends the walk),
CP-8 matching with the secondary rule, the background poller (06:45, 11:45, 16:45, 21:45,
4 per 24 hours, 2-hour skip, no backlog), the bilingual callback page (E-39), E-36 to E-38
and E-40 to E-44, link clearing in sync push step 7, attempt pruning at 04:00, the card_fetch
log line with aggregates only, KVITT_EB_* configuration. Tests against a local stub
(tests/cards_api/, 34 tests); the real API is never called.

Infra: Pi compose mounts secrets/cards read-only and passes the two application ids;
.env.example keys; dev stack stages infra/secrets/cards/; NPM block with the /cards/callback
gate line and unlogged location (kvitt.conf and README step 4); README "Card purchases".

Pre-commit hook bypassed (--no-verify, orchestrator's decision): the Android fast tests fail
in :domain VectorFilesTest (and the full check in :data ExampleRoundTripTest) because they pin
the contract's vector and example sets; matchCardPurchase and the card DTOs are K2's by design
(contract-first landing; K2 lands next). Server, contracts-check and web gates are green.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B

server/crates/kvitt-server/tests/cards_api/main.rs

@@ -0,0 +1,17 @@
+//! Card purchase tests (SPEC §9.12, FR-22, E-36 to E-44) against a local Enable Banking stub: connecting and the
+//! callback page, the windowed fetch and its mapping, matching and deletion, the background poller, the endpoints and
+//! their authorization, the link clearing on expense delete, the rate limit of the callback and the logging rule.
+//! The real Enable Banking API is never called.
+
+#[path = "../common/mod.rs"]
+pub mod common;
+pub mod stub;
+pub mod support;
+#[path = "../common/sync_fixtures.rs"]
+pub mod sync_fixtures;
+
+mod connect;
+mod endpoints;
+mod fetch;
+mod logging;
+mod poller;