test: add standardized test-utils with Pinia + i18n defaults

Recreates src/utils/test-utils.ts (removed in #10471) as the canonical
shared render wrapper for VTL component tests.

Provides:
- renderWithDefaults(): auto-configures Pinia (stubActions: false),
  vue-i18n (English), and common directive stubs (tooltip)
- Optional userEvent instance (opt out via setupUser: false)
- Re-exports screen from @testing-library/vue

Eliminates duplicated createTestingPinia + createI18n boilerplate
across 97+ test files.

Part of: COMP-02 (standardize Pinia store test mocking patterns)

src/utils/test-utils.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, it } from 'vitest'
+
+import { render, screen } from '@/utils/test-utils'
+
+import { defineComponent, h } from 'vue'
+
+const TestButton = defineComponent({
+  props: { label: { type: String, required: true } },
+  setup(props) {
+    return () => h('button', { 'data-testid': 'test-btn' }, props.label)
+  }
+})
+
+describe('test-utils', () => {
+  it('renders a component with default plugins', () => {
+    render(TestButton, { props: { label: 'Click me' } })
+    expect(screen.getByTestId('test-btn')).toHaveTextContent('Click me')
+  })
+
+  it('provides a userEvent instance by default', () => {
+    const { user } = render(TestButton, { props: { label: 'Click' } })
+    expect(user).toBeDefined()
+  })
+
+  it('allows opting out of userEvent', () => {
+    const { user } = render(TestButton, {
+      props: { label: 'Click' },
+      setupUser: false
+    })
+    expect(user).toBeUndefined()
+  })
+})

src/utils/test-utils.ts

@@ -0,0 +1,82 @@
+import type { RenderResult } from '@testing-library/vue'
+import type { ComponentMountingOptions } from '@vue/test-utils'
+
+import { createTestingPinia } from '@pinia/testing'
+import { render, screen } from '@testing-library/vue'
+import userEvent from '@testing-library/user-event'
+import { createI18n } from 'vue-i18n'
+
+import enMessages from '@/locales/en/main.json'
+
+/**
+ * Creates the default set of Vue plugins for component tests.
+ *
+ * - Pinia with `stubActions: false` (actions execute, but are spied)
+ * - vue-i18n with English locale
+ *
+ * Pass additional plugins via the `plugins` option in `renderWithDefaults`.
+ */
+function createDefaultPlugins() {
+  return [
+    createTestingPinia({ stubActions: false }),
+    createI18n({
+      legacy: false,
+      locale: 'en',
+      messages: { en: enMessages }
+    })
+  ]
+}
+
+/**
+ * Common directive stubs for components that use PrimeVue/custom directives.
+ * Prevents "Failed to resolve directive" warnings in test output.
+ */
+const defaultDirectiveStubs: Record<string, () => void> = {
+  tooltip: () => {}
+}
+
+type RenderWithDefaultsResult = RenderResult & {
+  user: ReturnType<typeof userEvent.setup> | undefined
+}
+
+/**
+ * Renders a Vue component with standard test infrastructure pre-configured:
+ * - Pinia testing store (actions execute but are spied)
+ * - vue-i18n with English messages
+ * - Common directive stubs (tooltip)
+ * - Optional userEvent instance
+ *
+ * @example
+ * ```ts
+ * import { render, screen } from '@/utils/test-utils'
+ *
+ * it('renders button text', async () => {
+ *   const { user } = render(MyComponent, { props: { label: 'Click' } })
+ *   expect(screen.getByRole('button')).toHaveTextContent('Click')
+ *   await user!.click(screen.getByRole('button'))
+ * })
+ * ```
+ */
+function renderWithDefaults<C>(
+  component: C,
+  options?: ComponentMountingOptions<C> & { setupUser?: boolean }
+): RenderWithDefaultsResult {
+  const { setupUser = true, global: globalOptions, ...rest } = options ?? {}
+  const user = setupUser ? userEvent.setup() : undefined
+
+  const result = render(component as Parameters<typeof render>[0], {
+    global: {
+      plugins: [...createDefaultPlugins(), ...(globalOptions?.plugins ?? [])],
+      stubs: globalOptions?.stubs,
+      directives: {
+        ...defaultDirectiveStubs,
+        ...globalOptions?.directives
+      }
+    },
+    ...rest
+  } as Parameters<typeof render>[1])
+
+  return { ...result, user }
+}
+
+export { renderWithDefaults as render, screen }