fix(ci): use REGISTRY_TOKEN for build-and-push registry login (CAR-1330)

Squashed fix swaps github.token → secrets.REGISTRY_TOKEN at .gitea/workflows/ci.yml:121, matching the proven-green cartsnitch/auth pattern (CAR-1009). Parity fix with uat PR #49 to prevent reintroduction on next dev→uat promotion.

Note: includes 3 absorbed lint/typecheck commits from PR #48 (already merged to dev via #48) to unblock CI on this branch. No app code changes; one-line CI config swap only.

QA: PR #50 approved by @cs_charlie (review id 4616); CI run 3443 lint/typecheck/test all green.
Co-authored-by: Barcode Betty <32+cs_betty@noreply.git.farh.net>
Co-committed-by: Barcode Betty <32+cs_betty@noreply.git.farh.net>

tests/conftest.py

@@ -117,7 +117,6 @@ def _register_event_listeners():
             event.listen(cls, "before_insert", _set_timestamp_defaults)
 
 
-
 TEST_JWT_SECRET = secrets.token_urlsafe(32)
 TEST_SERVICE_KEY = secrets.token_urlsafe(32)
 TEST_FERNET_KEY = "7reF42nmTwbdN21PBoubGp7h_FU8qSimstmlaMLoRK8="