feat: integrate AI-driven selection panel with context-aware text summarization and quiz generation features.

src/NexusReader.UI.Shared/wwwroot/js/knowledgeGraph.js

@@ -99,6 +99,10 @@ export function mount(containerId, data, dotNetHelper) {
 
 export function updateData(data) {
     if (!simulation || !rootGroup) return;
+    if (!data || !data.nodes) {
+        clear();
+        return;
+    }
 
     // Keep existing node positions if they match by ID
     const oldNodes = new Map(simulation.nodes().map(d => [d.id, d]));
@@ -261,3 +265,14 @@ export function zoomReset() {
     }
 }
 
+export function clear() {
+    if (!rootGroup) return;
+    rootGroup.select(".links-layer").selectAll("path").remove();
+    rootGroup.select(".nodes-layer").selectAll("g.node-group").remove();
+    if (badge) badge.style("display", "none");
+    if (simulation) {
+        simulation.nodes([]);
+        simulation.force("link").links([]);
+        simulation.stop();
+    }
+}

src/NexusReader.UI.Shared/wwwroot/js/selectionHandler.js

@@ -0,0 +1,41 @@
+export function initSelectionListener(dotNetHelper, container) {
+    if (!container) return;
+
+    console.log("[SelectionHandler] Initializing...");
+
+    const handleSelection = () => {
+        const selection = window.getSelection();
+        const text = selection.toString().trim();
+
+        if (text.length > 3) {
+            const range = selection.getRangeAt(0);
+            
+            // Look for the closest block-wrapper
+            let node = range.commonAncestorContainer;
+            if (node.nodeType !== 1) node = node.parentElement;
+
+            const blockNode = node.closest('[id]');
+
+                if (blockNode) {
+                    const rect = range.getBoundingClientRect();
+
+                    console.log("[SelectionHandler] Selection at screen coords:", rect.top, rect.left);
+
+                    dotNetHelper.invokeMethodAsync('HandleTextSelected', 
+                        text, 
+                        blockNode.id, 
+                        { 
+                            Top: rect.top, 
+                            Left: rect.left,
+                            Width: rect.width
+                        });
+                }
+        } else {
+            dotNetHelper.invokeMethodAsync('HandleSelectionCleared');
+        }
+    };
+
+    // Use multiple triggers for maximum reliability
+    document.addEventListener('selectionchange', handleSelection);
+    container.addEventListener('mouseup', () => setTimeout(handleSelection, 10));
+}