Proof

<this skill dir> is the absolute directory containing this installed SKILL.md.

• If checking code behavior → assertion: select the repository's existing relevant checks and observe their execution.
• If claiming performance → perf: record a baseline and changed run under the same inputs/environment; check correctness and an explicit threshold, not elapsed time alone.
• If checking a web UI → read references/visual-web.md; browser readiness and a user journey are mandatory.
• If checking a desktop UI → read references/visual-desktop.md; use one named CUA session and deterministic state verification.
• Before any selected branch → probe its sidecar prerequisites; missing tools block only that branch with the known install recipe. Availability does not establish service/browser readiness.
• Before adding checks → apply Delete → Repo → Stdlib → Minimal to unnecessary implementation additions; keep existing test conventions.
• If checks are declared → save a JSON manifest with checks and nonempty required_checks. Each check has id, literal argv, optional project-relative cwd, and optional timeout_ms (default 120000, maximum 3600000).
• If evidence artifacts are needed → include project-relative file paths in artifacts; keep generated logs/artifacts under the configured state directory so verification does not change source inputs.
• Execute node <this skill dir>/scripts/run.mjs checks.json --run-id <unique-id> --session <session-id> --branch <branch> from the project cwd. Use an absolute script path for installed skills.
• If the input digest changes during checks → treat the run as blocked, stabilize inputs and rerun. Never reuse another revision's pass.
• If execution fails, times out, or a command is missing → retain result/logs and report failed/blocked with a reason.
• If checks passed → run node <this skill dir>/scripts/check.mjs <run-id> against the current project before claiming done; exit 0 passes, exit 2 is blocked.
• If using Windows command shims → use a tested native executable or node <tool-cli.js> argv. The runner never enables a shell to execute a .cmd fallback.