[TheGreatAxios]

Last of the CL-12110 pull requests: the remaining .catch() calls, promise chains, the IIFE and the hand-rolled login poll.

Changes

• The four copies of the refusal-body read (human-fault.ts, api/artifacts.ts, api/projects.ts, workspace/index.tsx) share refusalBody in api/transport.ts. A body that is not JSON or cannot be read counts as "no body", so each caller shows its own wording; a read failure is logged, and anything else is rethrown.
• The query cache restore is a named async function. The cache is optional, so a failed restore is logged and the page paints with an empty cache instead of hanging on it.
• The promise chains in App.tsx, approaches-comparison.tsx, deliverable-block.tsx, pane-file.tsx, transcript.tsx, profiles.tsx, project-menu.tsx, settings.tsx, api/credentials.ts, single-flight.ts and load-room.ts are named async functions or try/finally blocks. The IIFE in loadProjectRoom is a named function.
• The session read in App.tsx catches only ApiFailure. The clipboard copy in transcript.tsx catches only DOMException. A failed approach choice now shows the hub's readable message when there is one.
• A subscription login is polled by a react-query QueryObserver with refetchInterval instead of a for loop with setTimeout. It is not tied to a component, so leaving the screen mid-sign-in still finishes the login, as before. The five-minute deadline stays, polling continues while the browser reports offline, a cancelled poll aborts its request, and a query marked meta: { persist: false } (the login poll) is kept out of the saved cache.

App.tsx's responseCode().then refusal chain is left to #171, which turns it into a named function.

Verification

• New tests: a refusal whose body cannot be read still gets the caller's own wording, and a non-JSON body gives no code; a login poll finishes on completion, rejects with the hub's message on failure, and rejects at its deadline.
• deliverable-block.tsx's version view and compare share one read.
• bun run lint, format:check, typecheck, test, pins:verify and vendor:verify pass.

[linear-code]

CL-12110

[corbits-triage]

Triage: Pass

No changes needed from you. A maintainer will review this pull request.

Stacked on #167: only this pull request's own changes were checked.

[corbits-triage]

No defects reported.