replace knowledge graph debugger with new visualizer. Fix renderer unmounting and cleanup

Author: felixzc8

frontend/app/src/components/chat/knowledge-graph-debug-info.tsx

@@ -42,6 +42,7 @@ export function KnowledgeGraphDebugInfo ({ group }: { group: ChatMessageGroup })
       loading={!shouldFetch || isLoading}
       loadingTitle={shouldFetch ? 'Loading knowledge graph...' : 'Waiting knowledge graph request...'}
       network={network}
+      useCanvasRenderer={true}
       Details={
         ({ target, network }) => {
           if (!canEdit) return null;

frontend/app/src/components/graph/components/NetworkCanvas.tsx

@@ -47,10 +47,10 @@ export function NetworkCanvas<Node extends NetworkNode, Link extends NetworkLink
     switch (target.type) {
       case 'node':
         renderer.focusNode(target.id);
-        return () => renderer.blurNode();
+        break;
       case 'link':
         renderer.focusLink(target.id);
-        return () => renderer.blurLink();
+        break;
     }
   }, [target, renderer]);