v0.36.2 — the sandbox knows this month's models

A coding-agent CLI resolves --model against its own allowlist, not your account's. The sandbox shipped claude 2.1.270, which answers a newer model id with [claude-code:unrecognized_model] and exits in under a second, having spent nothing — so a run started with such a model failed every attempt while the monitor said only "agent failed".

• The sandbox CLIs are current: claude 2.1.270 → 2.1.280, codex 0.154.0 → 0.156.1. OpenCode stays at 1.18.31.
• A rejected model names itself and the way out. The failure detail used to be the last line the CLI printed, which is its usage JSON — several hundred characters saying nothing. It now reads "unrecognized model 'X' — the sandbox's CLI doesn't know that id; use an alias like opus, or update the CLI in the mutator image", in the monitor, in report() and in metrics.jsonl.
• It fails once. A rejected request cannot come good on a retry, so the run stops on the first one instead of spending three iterations and two backoff waits on the same answer.

Worth knowing when you pick a model: the aliases (opus, sonnet, haiku, fable, default) are resolved by the CLI itself, so they can never go stale against the pinned image. A dated or versioned id can.

Both sandbox images are re-pinned; the arena rebuild is classified at major 2 — no scoring-path change, so the verified corpus carries over.