Harness Runtime

Shared CLI giving a skill the 6 harness conventions (config, on-disk audit, fail-open observability, evidence-bearing arbiter, dry-run, disk scoreboard) as ready primitives. Call it from a retrofitted skill instead of re-implementing curl-fail-open, redaction, append-only audit, and atomic state writes by hand. The operational sibling of devcycle (free-form per-skill checkpoints, no fixed gate order).

by @ericsantos