Correlation id becomes real ASP.NET Core middleware instead of a per-endpoint
read: every request gets one (client-supplied or generated), it's echoed as
an X-Correlation-Id response header, and pushed into the logging scope so
every log line for that request carries it — not just the Submit helper's,
verified against LogBrief which never threads it explicitly.
Idempotency-Key moves from per-HTTP-attempt (defeating its own purpose) to
per-logical-submit: runSubmit mints one key and threads it through a small
bridge (withIdempotencyKey/currentIdempotencyKey) since the NSwag-generated
client has no per-call header hook. Backend gains an IdempotencyStore that
short-circuits a replayed key to the first call's result instead of minting
a second reference — scoped to the Submit-helper endpoints per the WP's own
decision.
GET requests now retry transient failures (rxjs retry({count:2, delay:500}));
writes never auto-retry. Proven with a fake-HttpClient spec
(api-client.provider.spec.ts) rather than a manual network-tab check — the
WP's suggested `?scenario=error` check turned out not to exercise a real
network call at all (the interceptor throws before calling next()), so the
automated test is the actual proof.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
