refactor: Upload extractor, 429 refusal test, stricter contract test

docs/adr/0014-http-adapter-and-one-refusal-shape.md

@@ -10,7 +10,7 @@ feature, ADR-0009). `router.rs` assembles them; handlers reach use cases only th
 A JSON client previously met several failure bodies: `{"error": "..."}` from `ApiError`, bare
 status codes with empty bodies from handlers that returned `StatusCode::NOT_FOUND`, plain text from
 `domain_error_response`, axum's plain-text rejections for malformed `Json`/`Query`/`Path`, and the
-rate limiter's own 429 text. None of the refusals appeared in the OpenAPI document.
+rate limiter's own 429 text. The refusals were documented without a body schema.
 
 ## Decision
 
@@ -37,6 +37,9 @@ HTML and ActivityPub limiters keep axum-governor's default response.
 pages), redirects and statuses. ActivityPub-facing routes keep their status-only errors. Only JSON
 responses were unified.
 
+**Not covered.** Unmatched `/api/v1` paths (404) and wrong methods (405) are produced by the router
+itself and still return axum's empty bodies.
+
 **The spec says so.** Every operation documents at least one 4xx, every authenticated operation
 documents 401, and every 4xx/5xx references `ErrorResponse`. `tests/openapi_contract_test.rs`
 builds the spec from `http_axum::openapi::spec()` (no bootstrap) and fails when a new endpoint