Argon 3D Fidelity Atlas v171.0 — 860 models

Gemini 4 Argon deployed v171.0 (commit 98158f3): 860 real-world 3D models, 94.22M vertices, 178.51M triangles, 11,183/11,183 checks. Continues past the 855 (v170) desk. Catalog: public/catalog.json. Viewer: argon-3d-fidelity-atlas-e63fc6.gitlab.io. Standing 379 held.