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

infra/pi/.env.example

@@ -13,5 +13,11 @@ HA_HOST=CHANGE_ME
 KVITT_UID=1000
 # compose.yaml: gid both containers run as, `id -g` of the same user.
 KVITT_GID=1000
+# compose.yaml: the server's KVITT_EB_APP_ID, the Enable Banking application id for card purchases (SPEC §10.4,
+# D-175): the key file's name before .pem. Empty: card features off. The key goes to secrets/cards/enable-banking.pem.
+KVITT_EB_APP_ID=
+# compose.yaml: the server's KVITT_EB_MEMBER_APP_ID, only for a member's own application (CP-13 fallback); empty: the
+# member uses KVITT_EB_APP_ID. Its key goes to secrets/cards/enable-banking-member.pem.
+KVITT_EB_MEMBER_APP_ID=
 # compose.yaml: the backup's Google Drive folder id (OQ-4).
 RCLONE_FOLDER_ID=1jDp1dGE5R3H2DBcXCqIPN1iWzQnPkdlV