Land a succeeded draft only on a plan read from the server

A redraft keeps the plan's id, so a plan the service worker answered from
its cache could pass for the finished rebuild. The API client's apiRead now
says whether a GET was the cached copy; the plan carries it, and the Draft
board shows the retryable draft-unread error instead of a cached plan with
the drafted id. A later read from the server still lands the draft.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/api/index.ts

@@ -1,5 +1,5 @@
 export { ApiProvider, useApi } from './ApiContext.tsx'
-export { createApiClient, CSRF_HEADER, ME_PATH, type ApiClient, type ApiLocation, type ApiRequest, type Me } from './client.ts'
+export { createApiClient, CSRF_HEADER, ME_PATH, type ApiClient, type ApiRead, type ApiLocation, type ApiRequest, type Me } from './client.ts'
 export { ApiError } from './errors.ts'
 export { createQueryClient, shouldRetry } from './queryClient.ts'
 export { createVerifiedSession, VERIFIED_SESSION_KEY, type VerifiedSession } from './verifiedSession.ts'