HarfangLab answers a 500 now and then on a call that passes when sent
again. Each script's request() now retries up to three times (1, 2, 4 s):
GET on 429/500/502/503/504, writes only on 429/502/503 so an isolation,
a kill or a job is never sent twice.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>