feat: remove EditableConnectionsExample and related imports; clean up unused connection spatial index logic and props in demos

Author: pavanpodila

packages/demo/lib/embed_wrapper.dart

@@ -16,19 +16,19 @@ class DeferredExampleLoader extends StatefulWidget {
 }
 
 class _DeferredExampleLoaderState extends State<DeferredExampleLoader> {
-  late Future<Widget> _loadFuture;
+  late Future<void> _loadFuture;
 
   @override
   void initState() {
     super.initState();
-    _loadFuture = widget.example.load(context);
+    _loadFuture = widget.example.load();
   }
 
   @override
   void didUpdateWidget(DeferredExampleLoader oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (oldWidget.example.id != widget.example.id) {
-      _loadFuture = widget.example.load(context);
+      _loadFuture = widget.example.load();
     }
   }
 
@@ -40,14 +40,15 @@ class _DeferredExampleLoaderState extends State<DeferredExampleLoader> {
     }
 
     // Otherwise show loading indicator while loading
-    return FutureBuilder<Widget>(
+    return FutureBuilder<void>(
       future: _loadFuture,
       builder: (context, snapshot) {
         if (snapshot.connectionState == ConnectionState.done) {
           if (snapshot.hasError) {
             return _ErrorView(error: snapshot.error.toString());
           }
-          return snapshot.data!;
+          // Build synchronously after async load completes
+          return widget.example.build(context);
         }
         return const _LoadingView();
       },

packages/demo/lib/example_model.dart

@@ -28,11 +28,10 @@ class Example {
   /// Whether this example has been loaded.
   bool get isLoaded => _cachedBuilder != null;
 
-  /// Loads the example and returns the widget.
-  /// Caches the builder after first load.
-  Future<Widget> load(BuildContext context) async {
+  /// Loads the example's deferred library.
+  /// After this completes, [build] can be called safely.
+  Future<void> load() async {
     _cachedBuilder ??= await loader();
-    return _cachedBuilder!(context);
   }
 
   /// Builds the widget synchronously if already loaded.

packages/demo/lib/examples/editable_connections.dart

@@ -1119,24 +1119,4 @@ extension NodeApi<T, C> on NodeFlowController<T, C> {
       );
     });
   }
-
-  /// Rebuilds spatial index for a single connection using accurate path segments.
-  void _rebuildSingleConnectionSpatialIndex(Connection<C> connection) {
-    if (!isConnectionPainterInitialized || _theme == null) return;
-
-    final sourceNode = _nodes[connection.sourceNodeId];
-    final targetNode = _nodes[connection.targetNodeId];
-    if (sourceNode == null || targetNode == null) return;
-
-    final pathCache = _connectionPainter!.pathCache;
-    final connectionStyle = _theme!.connectionTheme.style;
-
-    final segments = pathCache.getOrCreateSegmentBounds(
-      connection: connection,
-      sourceNode: sourceNode,
-      targetNode: targetNode,
-      connectionStyle: connectionStyle,
-    );
-    _spatialIndex.updateConnection(connection, segments);
-  }
 }