v6.4.2 — Rate-limit field fix (Codex review)

Fixes a regression found by Codex adversarial review in v6.4.1.

Fixed

• Rate-limit detection checked wrong field — read_results.py only checked run.error (LangSmith run-level, usually None for subprocess failures) but 429 errors from agent subprocesses go into run.outputs["error"]. Now checks both run.error and outputs.error with the RATE_LIMIT_RE regex.

Install: npx harness-evolver@latest

Full changelog: https://github.com/raphaelchristi/harness-evolver/blob/main/CHANGELOG.md