# ISSUE #140: Artifact Export and Model Metadata

**Status:** `status:todo`
**Parent:** #139 (GENESIS)
**Depends On:** #139 (Workstation Foundation)

## Summary
Owns the generation and validation of real model artifacts (IREE/ONNX) and their associated metadata. This issue is strictly about artifact production, not placeholders.

## Tasks
- [ ] **IREE/ONNX Artifact Generation**: Produce ready-to-execute bytecode (.vmfb) and .onnx files for Magenta RT and MIDI models.
- [ ] **Quantized Artifacts**: Generate 4-bit (NF4) and INT8 variants optimized for the RX 6700 XT.
- [ ] **Metadata Specification**: Create `artifact_metadata.json` for each model defining input/output shapes, quantization levels, and performance targets.
- [ ] **Fail-Closed Validation**: Implement a script to verify that generated artifacts match the metadata and are loadable by the NNE runtime.

## Acceptance Criteria
- [ ] No dummy graph exports or placeholder benchmarks.
- [ ] All artifacts saved to `Content/MagentaRT/Models/`.
- [ ] Metadata correctly identifies 800M Mother vs 200M Submodel paths.