Stopping at a plan-limit warning #1008

Parent

#977

What to build

thirdshift reads each Harness's limit warnings:

• Claude's rate-limit events, both warnings and rejections;
• Codex's rate-limit reports, at a threshold;
• the other Harnesses' warnings, once Live checks for the Trial sandbox #1009's checks show how each one reports them.

At a warning, an Experiment starts no new Trial, and a Trial cut short is void. The Experiment pauses until it's run again. #978's Scoring run uses the same detection.

Acceptance criteria

• Stream tests detect Claude's warning and rejection events and Codex's limit reports.
• An Experiment that sees a warning starts no new Trial and pauses, and running it again resumes it.
• Runs are unaffected. Only Experiments and the Scoring run stop.