.

frontend/assets/js/app.js

@@ -1184,12 +1184,16 @@ function renderNodeToolbar() {
 
 function setupCanvasDrop() {
     const wrapper = document.getElementById('networkCanvasWrapper');
+    let dropPending = false;
     wrapper.addEventListener('dragover', (e) => { e.preventDefault(); e.dataTransfer.dropEffect = 'copy'; });
     wrapper.addEventListener('drop', async (e) => {
         e.preventDefault();
         e.stopPropagation();
-        suppressNextMouse = Date.now() + 300;
+        if (dropPending) return;
+        dropPending = true;
+        suppressNextMouse = Date.now() + 500;
         const data = e.dataTransfer.getData('text/plain');
+        if (!data) { dropPending = false; return; }
         const rect = canvas.getBoundingClientRect();
         const mx = e.clientX - rect.left - panX;
         const my = e.clientY - rect.top - panY;
@@ -1204,7 +1208,6 @@ function setupCanvasDrop() {
                 color: '#1e3a5f', border_color: '#3b82f6',
                 opacity: 0.15, z_index: nextShapeZ++
             })});
-            loadNetworkData();
         } else {
             await apiFetch('nodes', { method: 'POST', body: JSON.stringify({
                 label: data.charAt(0).toUpperCase() + data.slice(1),
@@ -1212,8 +1215,9 @@ function setupCanvasDrop() {
                 group_name: 'default', notes: '',
                 pos_x: mx, pos_y: my
             })});
-            loadNetworkData();
         }
+        await loadNetworkData();
+        dropPending = false;
     });
 }