fix(graph-view): keep canvas host mounted when hover label toggles

Render HoverNode after the force-graph container so index-based
reconciliation does not remount the host and wipe the graph.

Author: cursoragent

plugins/sanity-plugin-graph-view/src/tool/GraphView.tsx

@@ -561,12 +561,13 @@ export default function GraphView({
             </LegendRow>
           ))}
         </Legend>
-        {hoverNode && <HoverNode theme={theme}>{labelFor(hoverNode.doc)}</HoverNode>}
         <div
           ref={(element) => {
             if (element) setContainer(element)
           }}
         />
+        {/* After the canvas host so toggling hover does not remount it (index reconciliation). */}
+        {hoverNode && <HoverNode theme={theme}>{labelFor(hoverNode.doc)}</HoverNode>}
       </GraphRoot>
     </GraphWrapper>
   )