# Validation and provenance

## Authoring

Adam MCP task **e98296f8-ab8b-4f9f-8faa-f74d64ee4d7a**, titled “Concept 27 CAD Handoff,” authored the CAD builder and design parameters from the supplied Concept 26 v12.3 package and approved inspiration image. The builder was executed unchanged locally in an isolated Python environment to export and review this handoff.

- Adam builder SHA-256: `3fbb297edefe34fbb2b8216191640d01b3e3f3626ed7dc5f66b9ea2929d2a37e`
- Adam parameters SHA-256: `9e8b8ae74e4789031031a37a4cb1ffc5c787e469ba391b0f7cb02482397b1d5a`
- Original user ZIP SHA-256: `9013900e9cdf75894223f1e5ef19728d170c84c49065cd07093d9730c0f5b5de`
- Authoritative source STEP SHA-256: `1c3a53a9581d02c65467800a93c45a671985578bcf9b457cc78b7a64e68f152c`

Codex performed independent geometry checks, corrected the preview exporter, rendered the actual CAD meshes and assembled these handoff notes. The source CAD inputs and Adam's geometry builder/parameters were preserved. This release uses the verified Adam CAD checkpoint; extended remote hardware/motion audit results are not claimed as completed or passed here.

## Completed checks

| Check | Result |
| --- | --- |
| Assembled STEP | Valid BRep containing 17 valid positive-volume solids |
| Individual STLs | All 17 watertight, consistently wound and positive-volume |
| Overall bounds including controls | Approximately 83.35 × 152.70 × 24.739 mm |
| Manufactured-part intersections at rest | Only the inherited shell/lens press fit, 0.592018 mm³ |
| Grille preservation | All 121 source centers/radii retained: 32 × Ø1.4, 48 × Ø1.8, 41 × Ø2.2 mm |
| Microphone port | New center port open; original offset port filled |
| Sampled source-surface comparison | Back shell, clamp, front action envelope and front outside the moved microphone region support preservation; see diagnostics below |
| GLB materials/frame | 17 named components assigned to intended materials; Y-up and metre-scale bounds verified |
| GLB normals | No reversed-facing or degenerate triangles in exporter checks; flat-front normals remain +Z to numerical precision |

The `preview/preview_verification.json` records hashes of the unchanged GLB binary geometry buffers and the reviewed material assignments. The regenerated portable exporter produces those same geometry buffers. `validation/glb_normals_materials.json` records the final portable export check.

## Reading the diagnostic files

`validation/adam_checkpoint_geometry.json` records solid metrics and pairwise rest-position intersections. Its assembly hash identifies the STEP used for the independent review.

`validation/independent_surface_comparison.json` is a sampled mesh comparison, not a proof of exact BRep identity. Its front-shell threshold initially reports false because differently tessellated versions of the same trimmed surface yield a few sample offsets. The follow-up `surface_outlier_probe.json` projects those outliers onto the exact CAD shell and compares the resulting exact surface points; the maximum measured cross-surface distance is approximately **1.78e-15 mm**. The original diagnostic is retained rather than relabeling its raw sample result.

Coincident Boolean source comparisons also produced invalid OCCT result shapes on some unchanged parts. Those results were treated as inconclusive kernel diagnostics, not as physical missing material or a passed difference-volume test. The source-preservation review therefore uses part construction provenance, sampled surfaces and the exact-surface follow-up.

`validation/checkpoint_review_summary.json` collects the findings and their scope. `validation/package_verification.json` records final file hashes, reference-input preservation, mesh checks and preview reproducibility for this assembled package.

## Limits

This release does not certify internal hardware placement, button motion, a native Fusion feature timeline, manufacturability, fastening, soft-part installation, adhesive performance, acoustics, RF performance or environmental ratings. The inherited enclosed clamp pilot cavities are a concrete assembly issue and are described in `ASSEMBLY_AND_OPEN_ITEMS.md`. A physical prototype and a resolved fastening arrangement are needed before fabrication release.