Turn a set of flagged production call logs into evaluator scenarios for a Cekura agent — cluster the failures into reproducible modes and create one scenario per cluster. Use when the user says "create scenarios from failed calls", "build evaluators for prod failures", "turn call logs into scenarios", "simulate the failures we saw in prod", "replay these bad calls as tests", "regression-test the agent on prod issues", or hands over a set of flagged call IDs to harden the agent against. The flagged set normally comes from `cekura-flag-call-log-failures`; if the user hasn't triaged yet, run that skill first. This skill takes the flagged calls as given — it does NOT re-mine or re-triage — clusters by failure mode, drafts one scenario per cluster, and optionally creates them via the scenarios API (or the call-logs → scenarios endpoint). Also supports a single-call fast path: given one call log ID (or an observe URL), reproduce just that call as one evaluator scenario.