feat(dees-dashboardgrid): enhance widget placement validation and logging for drag-and-drop interactions

ts_web/elements/dees-dashboardgrid/dees-dashboardgrid.ts

@@ -413,20 +413,42 @@ export class DeesDashboardgrid extends DeesElement {
 
     const layoutSource = this.widgets;
     this.previewWidgets = null;
+
+    // Always validate the final position, don't rely on lastPlacement from drag
     const target = this.placeholderPosition ?? dragState.start;
-    const placement =
-      dragState.lastPlacement ??
-      resolveWidgetPlacement(
-        layoutSource,
-        dragState.widgetId,
-        { x: target.x, y: target.y },
-        this.columns,
-        dragState.previousPosition,
-      );
+    const placement = resolveWidgetPlacement(
+      layoutSource,
+      dragState.widgetId,
+      { x: target.x, y: target.y },
+      this.columns,
+      dragState.previousPosition,
+    );
 
     if (placement) {
-      this.commitPlacement(placement, dragState.widgetId, 'widget-move');
+      // Verify that the placement doesn't result in overlapping widgets
+      const finalWidget = placement.widgets.find(w => w.id === dragState.widgetId);
+      if (finalWidget) {
+        const hasOverlap = placement.widgets.some(w => {
+          if (w.id === dragState.widgetId) return false;
+          return (
+            finalWidget.x < w.x + w.w &&
+            finalWidget.x + finalWidget.w > w.x &&
+            finalWidget.y < w.y + w.h &&
+            finalWidget.y + finalWidget.h > w.y
+          );
+        });
+
+        if (!hasOverlap) {
+          this.commitPlacement(placement, dragState.widgetId, 'widget-move');
+        } else {
+          // Return to start position if overlap detected
+          this.widgets = this.widgets.map(widget =>
+            widget.id === dragState.widgetId ? { ...widget, x: dragState.start.x, y: dragState.start.y } : widget,
+          );
+        }
+      }
     } else {
+      // Return to start position if no valid placement
       this.widgets = this.widgets.map(widget =>
         widget.id === dragState.widgetId ? { ...widget, x: dragState.start.x, y: dragState.start.y } : widget,
       );