[jm-rivera]

The site answered its own refusals in two shapes: problem documents for the routes website#54 touched, and {error, retry, detail} or {detail} bodies everywhere else, which the client contract in DevelopmentFinanceObservatory/spec-kit#20 now retires. A timed-out search part also showed "No data matched this query.", because the vendored client predated the timed_out no-data reason.

Every HTTP refusal the site builds is now an application/problem+json document from src/lib/proxy/problem.ts, with type, title, status, detail, code, retryable and trace_id, and the x-dfo-trace-id header. That covers the proxy's 429 (rate_limited, with its rate-limit headers and Retry-After) and 502 (transient_unavailable) in forward.ts, forwardAsset, the /codes/[code] and Studio routes, the Studio allowance in spendPrompt.ts, and the share, conversations, roadmap votes, events, source-doc, version-download, download-pin and live-share routes. A code the API registry or proxy-codes.json holds links type to /codes/<code>; a site code (guest_limit, live_*, refresh_pending, unauthorized and the rest) reads about:blank. problem() places extension members first, so none can override a core member. Readers read code: readShareAnswer, liveCards, cardDownload.liveRefusal (which takes the wait from Retry-After), and createSearchShare, which reads the platform's own code from platform_code only on a platform_refused share, so a 400 or 413 shows the generic share failure again.

vendor/developmentfinance-client-0.1.0.tgz is rebuilt from DevelopmentFinanceObservatory/sdk (the problem-document client), and only its integrity line moves in pnpm-lock.yaml. view.ts gains the timed_out text and readings.ts the breakdown basis note the new types require. docs/development.md notes that a local re-vendor needs the old copy under node_modules/.pnpm removed, since the file name does not change.

Left as they are: /api/feedback, which mirrors the brochure site's {ok, message}, and the plain-text s/[id]/download and docs-md responses. liveBackend.refusalOf keeps its error fallback because the dfo-ai backend still sends {error} bodies.

A reviewer should check the code chosen for each route and that relayed upstream responses pass unchanged.

Testing: pnpm typecheck and pnpm lint passed, prettier passed on the changed files, and pnpm test passed 1,879 tests including db/test against Postgres 18.4.