style: format frontend with prettier

Mechanical one-shot pass of pnpm format over src/, tests/, tools/, and
root configs. No functional changes; build and type-check verified.

tests/example.spec.ts

@@ -1,18 +1,18 @@
-import { test, expect } from '@playwright/test';
+import { test, expect } from '@playwright/test'
 
 test('has title', async ({ page }) => {
-  await page.goto('https://playwright.dev/');
+  await page.goto('https://playwright.dev/')
 
   // Expect a title "to contain" a substring.
-  await expect(page).toHaveTitle(/Playwright/);
-});
+  await expect(page).toHaveTitle(/Playwright/)
+})
 
 test('get started link', async ({ page }) => {
-  await page.goto('https://playwright.dev/');
+  await page.goto('https://playwright.dev/')
 
   // Click the get started link.
-  await page.getByRole('link', { name: 'Get started' }).click();
+  await page.getByRole('link', { name: 'Get started' }).click()
 
   // Expects page to have a heading with the name of Installation.
-  await expect(page.getByRole('heading', { name: 'Installation' })).toBeVisible();
-});
+  await expect(page.getByRole('heading', { name: 'Installation' })).toBeVisible()
+})