Port of upstream grok-build 1.0.0/1.0.1-window retry policy.
- is_retryable_api_status: 429 plus any 5xx except Cloudflare 525/526
(origin TLS handshake / invalid certificate — never clears on its
own), replacing the 500|502|503|504|520 allowlist so the 521-524,
529, and 530 edge pages an outage serves actually retry.
- The generic retry path clamps a server Retry-After to
MAX_RETRY_BACKOFF (30s) and jitters it: Cloudflare 52x pages ask for
60-120s, which across the budget stalled a turn ~28 minutes. The 429
path keeps the full (parse-capped) Retry-After under its low attempt
cap, and jitter is shared via jittered().
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KSy9S31pZNWXtRZNVJ1sDf
ZacharyZhang-NYandClaude Fable 5
25d1a4f980