Explain the Playwright configuration file and its key options

The playwright.config.js file controls test execution behavior and browser settings.

Key configuration options:

module.exports = {
  // Test directory
  testDir: './tests',
  
  // Global timeout for each test
  timeout: 30000,
  
  // Global setup and teardown
  globalSetup: './global-setup.js',
  globalTeardown: './global-teardown.js',
  
  // Retry failed tests
  retries: 2,
  
  // Parallel execution
  workers: process.env.CI ? 1 : undefined,
  
  // Reporter configuration
  reporter: [['html'], ['junit', { outputFile: 'results.xml' }]],
  
  // Browser and context settings
  use: {
    baseURL: 'http://localhost:3000',
    headless: true,
    screenshot: 'only-on-failure',
    video: 'retain-on-failure',
    trace: 'on-first-retry'
  },
  
  // Multiple browser projects
  projects: [
    { name: 'chromium', use: { ...devices['Desktop Chrome'] } },
    { name: 'mobile', use: { ...devices['iPhone 12'] } }
  ]
};