Sort dataset dropdown alphabetically by display name

app.py

@@ -118,8 +118,8 @@ def index():
 @app.route("/api/datasets")
 def get_datasets():
     """Return list of available datasets for the UI dataset selector."""
-    return jsonify(
-        [
+    items = sorted(
+        (
             {
                 "slug": slug,
                 "display_name": adapter.display_name,
@@ -128,8 +128,10 @@ def get_datasets():
                 "has_ground_truth": adapter.has_ground_truth,
             }
             for slug, adapter in REGISTRY.items()
-        ]
+        ),
+        key=lambda d: d["display_name"].lower(),
     )
+    return jsonify(items)
 
 
 @app.route("/api/<dataset_slug>/problems")