Add artifact configuration for Hub download counting

Expose the existing artifact packaging metadata through a default Hub query filename. Existing weights, runtime files, and research/draft status are unchanged.

config.yaml

@@ -0,0 +1,20 @@
+{
+  "schema": "shapleymcg.artifact-configuration.v1",
+  "repo_id": "brandonmusic/GLM-5.3-EXL3-TR3-3bpw",
+  "status": "draft",
+  "packaging": "routed EXL3/TR3 shards and MTP K5 overlay; non-routed BF16 components required separately",
+  "base_model": "zai-org/GLM-5.3-BF16",
+  "base_model_identity_file": "evidence/source-inventory.json",
+  "routed_experts": {
+    "directory": "materialized-uniform-k3",
+    "bits_per_weight": 3,
+    "manifest": "materialized-uniform-k3/MANIFEST.json",
+    "manifest_sha256": "c36f1203ea54d360d2fbf3ebc2901d5d33b865dce5cbb2d7044905a6c9340f3a"
+  },
+  "mtp": {
+    "directory": "mtp78-k5",
+    "bits_per_weight": 5
+  },
+  "usage_documentation": "README.md",
+  "configuration_scope": "Artifact packaging descriptor; not a Transformers AutoConfig or a standalone-model compatibility claim."
+}