Add browser inference sample manifest

sample_manifest.json

@@ -0,0 +1,17 @@
+{
+  "demo_id": "demo_20260404_083520",
+  "scenario_id": "glucose",
+  "dataset_id": "glu-sec01-core",
+  "dataset_title": "glu-sec01-core",
+  "rows": [],
+  "feature_keys": [
+    "glucose",
+    "insulin",
+    "meal_load"
+  ],
+  "target_key": "target_glucose",
+  "summary": {
+    "row_count": 0,
+    "source": "none"
+  }
+}