test: fix vitest mock gtm api

test/setup.ts

@@ -1 +1,20 @@
+import { vi } from 'vitest'
 import 'fake-indexeddb/auto'
+
+// Mock useScriptGoogleTagManager globally
+vi.stubGlobal('useScriptGoogleTagManager', () => ({
+  proxy: {
+    dataLayer: {
+      push: vi.fn(),
+    },
+  },
+}))
+
+// Mock onMounted to prevent Vue warnings in tests
+vi.mock('vue', async () => {
+  const actual = await vi.importActual('vue')
+  return {
+    ...actual,
+    onMounted: vi.fn(),
+  }
+})