## Why
Reusable clients need fresh authentication for each request while preserving the credential source and transport policy selected when the client was created.
## What changed
- Add runtime-aware backend client construction and per-request authentication. Allow token refresh within the original credential source, reject credential replacement, and validate destination and account/organization selectors.
- Let runtime authentication finish persisting rotated tokens when the requesting task is cancelled.
- Apply asynchronous authentication to file creation and finalization requests, generating fresh assertions while keeping credentials off blob uploads.
- Preserve direct sandbox routing without enabling legacy custom-CA fallback for protected clients that reject redirects.
- Exclude login account metadata from model cache identities when provider bearer credentials override the login, and record authentication selection outcomes and duration.
## Testing
Add regression coverage for credential refresh and replacement, organization selection, destination restrictions, transport policy preservation, cancellation during token rotation, credential stripping on redirects, and file upload authentication in both runtime authentication modes.
GitOrigin-RevId: d045595e869dfcdfd9f705a6228cf0eb4c2d2c12
## Why
Token plan claims can be stale, and the active account or user can change while a request is in flight. Analytics report selection and account-bound response data need to reflect the verified identity and current server plan.
## What changed
- Fetch the active account's plan once per analytics session and use it to select report endpoints and supported credit breakdowns.
- Add report loading with a fixed end date, account-scoped response caching, and token model filtering. Reuse payloads across grouping changes and evict invalid cached responses so requests can retry.
- Prefer complete attribution for usage breakdowns within the requested range; retain legacy surface/model data when attribution is incomplete and include all features in turn-start breakdowns.
- Add cancellable report-loading state with timeout and interruption errors, and preserve actionable sign-in and retry messages.
- Recheck the active identity after rate-limit reads before exposing account-bound fields.
## Testing
Add regression tests for server plan discovery, report routing and caching, model filtering, attribution fallback, failed-request retries, load cancellation, authentication recovery, and account or user changes during requests.
GitOrigin-RevId: 45c4c09f108c9703893f3ed15613437ebd7c74a8
cooper-oai