Registry: add Lens artifacts for gemma-4-12b-it-Q4_K_M (via atlas lens publish)

[itigges22]

Add Lens artifacts for gemma-4-12b-it-Q4_K_M (auto-generated by atlas lens publish)

Summary

User-trained Geometric Lens cost-field for gemma-4-12b-it-Q4_K_M, uploaded to
HuggingFace at https://huggingface.co/itigges22/atlas-lens-gemma4-12b.

Verification checklist (maintainer review per PC-059)

• HF link reachable: https://huggingface.co/itigges22/atlas-lens-gemma4-12b
• License is permissive for redistribution (apache-2.0)
• cost_field.pt SHA256 matches: 82b2d960b71b84a90ecc69189c67bc72a9b7cbc5c79b7b207dcaf2634b0af509
• Artifact input dim (3840) matches the base model's embedding dim
• Spot-check: download + run atlas lens check against the base model

Suggested registry diff

Add the following to atlas/cli/commands/model_registry.py (or update
the existing entry's lens_status from no-artifacts/unverified
to supported):

Model(
    name="gemma-4-12b-it-Q4_K_M",
    # ... existing tier / model_file / model_size_gb / download_url ...
    lens_status="supported",
    lens_artifact_dir=None,  # uses ATLAS_LENS_MODELS dir; per-model layout TBD by PC-058 follow-on
    lens_artifact_files=['cost_field.pt', 'cost_field.safetensors', 'gx_xgboost.json', 'gx_weights.json'],
    license="apache-2.0",
),

Provenance

Trained locally via atlas lens build against gemma-4-12b-it-Q4_K_M. Contrast
the merged behavior with the prior lens_status: {no-artifacts | unverified}
state — atlas doctor should stop warning about lens drift on this model
once the PR merges.

[itigges22]

Superseded by a combined-publish PR (atlas publish, PC-215).