# Cleanroom and independent review report

## Outcome

The exact prompt was executed once in an empty workspace by an isolated Codex agent using Burr skill commit `3a1b8ebf17e178b28c6d65f67ad04fc97f009a55` and CAD skill commit `fc4f7069fb31c131a55f1ecd334b505f031f486b`.

Prompt SHA-256: `3c9f24162b60f47c980407762831950fe5c1894924433af9f205b289d80082fc`.

No earlier hanger geometry was provided, and no parent-agent steering occurred after execution began. No purchase, fabrication, physical use, publication, or external contact occurred during the run.

## Reproduced digital evidence

- CAD provider validation: 16/16 targets passed with zero failures.
- Deployed shoulder width: 442 mm.
- Folded envelope: 222.884518 × 88 × 30 mm.
- Hook pocket: 42 mm for a stated maximum 38 mm rod.
- Pin/bore clearance: 0.6 mm diametral.
- Positive-lock engagement: 6 mm per arm, with a nominal 36 mm² contact face per side.
- Release travel: 7.5 mm with 1 mm modeled blocking-face clearance.
- Exact exported STEP validation: all 55 component pairs passed in deployed, 25%, 50%, 75%, and folded poses.
- Burr motion: 61 rigid frames, 11 instances, 1600 ms.

The independent review reran the geometry validator from a separate temporary copy and reproduced `overall_pass: true` and all five zero-positive-volume-intersection results.

## Burr result

Burr's check is not a pass:

- Deployed: `fail`, four findings, 11 components, 55 checked pairs.
- Folded: `fail`, three findings, 11 components, 55 checked pairs.
- Both include `open_component_mesh` for seven tessellated components.

The exact BREP result and Burr's tessellated result use different representations. Both are retained; the BREP result does not override Burr's failed/incomplete outcome.

## Trust boundary

Trusted: editable source, exported CAD, stated dimensions, exact five-pose geometry result, named Burr motion, and the preserved evidence files.

Not trusted: physical load rating, stiffness, fatigue, creep, spring selection, retention force, dimensional accuracy after printing, user safety, or production readiness.