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

contracts/examples/E-37-card-auth/request.json

@@ -0,0 +1,5 @@
+{
+  "provider_id": "sj_prio_mastercard",
+  "history_days": 30,
+  "client": "android"
+}

contracts/examples/E-37-card-auth/response.json

@@ -0,0 +1,9 @@
+{
+  "id": "0192c300-0000-7000-8000-000000000001",
+  "provider_id": "sj_prio_mastercard",
+  "status": "pending",
+  "failure": null,
+  "auth_url": "https://bank.example.invalid/authorize?session=example",
+  "expires_at": "2026-10-24T10:15:00.000Z",
+  "connection": null
+}