fix(python): accurate LLM hint and exit 124 on Monty time limit - #2833

Requested by Михайло · project thread

What changed

• The embedded python3 LLM hint describes what Monty actually runs: the real stdlib list (json, datetime, unicodedata were missing), re disabled, simple classes only (no inheritance), no match, output via print(). A new test imports every module the hint names and checks the class/match/re claims, so the next Monty upgrade that changes them fails the build instead of silently misleading agents.
• A Monty time-limit hit exits 124 with python3: execution timed out after Ns, keeping earlier output, the same as the CPython runtime and coreutils timeout. A script's own TimeoutError is still an ordinary exit-1 exception.

Why

Found reviewing a downstream integration (harnx): its docs had to warn users that bashkit's "no classes" hint is wrong, and its backend greps stderr for TimeoutError: time limit exceeded: to tell a timeout from a script error.

Before / After

Before:

$ bashkit -c "python3 -c 'print(1)
while True: pass'; echo rc=\$?"     # max_duration 200ms
1
Traceback (most recent call last): ...
TimeoutError: time limit exceeded: 200.1ms > 200ms
rc=1

After: stdout 1\nrc=124, stderr python3: execution timed out after 0.2s (timeout_limit_exits_124). Hint before: ... No HTTP/network. No classes. No third-party imports.; after: see Python::llm_hint, enforced by test_llm_hint_matches_runtime.

Risk

• Low
• Scripts checking for exit 1 on a Monty timeout now see 124.

Checklist

• Tests added or updated
• Backward compatibility considered

Generated by Claude Code

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