fix(test): add PointerEvent polyfills and update drag interaction test to match implementation

tests/frontend/setup.js

@@ -1,6 +1,35 @@
 import { afterEach, beforeEach } from 'vitest';
 import { resetDom } from './utils/domFixtures.js';
 
+// Polyfill PointerEvent for jsdom environment
+if (typeof window !== 'undefined' && !window.PointerEvent) {
+  class PointerEvent extends MouseEvent {
+    constructor(type, eventInit = {}) {
+      super(type, eventInit);
+      this.pointerId = eventInit.pointerId || 0;
+      this.pointerType = eventInit.pointerType || 'mouse';
+      this.isPrimary = eventInit.isPrimary !== undefined ? eventInit.isPrimary : true;
+    }
+  }
+  window.PointerEvent = PointerEvent;
+}
+
+// Polyfill setPointerCapture and releasePointerCapture for jsdom elements
+if (typeof Element !== 'undefined') {
+  const capturedPointers = new Map();
+
+  Element.prototype.setPointerCapture = function(pointerId) {
+    capturedPointers.set(pointerId, this);
+  };
+
+  Element.prototype.releasePointerCapture = function(pointerId) {
+    capturedPointers.delete(pointerId);
+  };
+
+  // Store captured pointers for potential use in tests
+  window.__testCapturedPointers = capturedPointers;
+}
+
 beforeEach(() => {
   // Ensure storage is clean before each test to avoid cross-test pollution
   localStorage.clear();