feat: integrate Playwright for E2E testing and enhance testing framework

- Added Playwright for end-to-end testing in the `apps/web` module, including a new `login.spec.ts` for testing login functionality.
- Updated package.json to include Playwright dependencies and new test commands for E2E testing.
- Enhanced .gitignore to exclude Playwright test results and reports.
- Modified existing documentation to reflect the integration of Playwright and updated testing guidelines.
- Refactored test commands to streamline the testing process, including a dedicated command for E2E tests.

These changes improve the testing framework by providing robust E2E testing capabilities, enhancing the reliability and quality of the application.

apps/web/playwright.config.ts

@@ -0,0 +1,25 @@
+import { defineConfig, devices } from '@playwright/test';
+
+const E2E_PORT = Number(process.env.E2E_PORT ?? 4173);
+const E2E_ORIGIN = `http://127.0.0.1:${E2E_PORT}`;
+
+export default defineConfig({
+  testDir: './e2e',
+  fullyParallel: true,
+  forbidOnly: Boolean(process.env.CI),
+  retries: process.env.CI ? 2 : 0,
+  reporter: 'list',
+  timeout: 60_000,
+  use: {
+    baseURL: E2E_ORIGIN,
+    trace: 'on-first-retry',
+    screenshot: 'only-on-failure',
+  },
+  webServer: {
+    command: `pnpm run copy:brand && vite --clearScreen false --host 127.0.0.1 --port ${E2E_PORT} --strictPort`,
+    url: E2E_ORIGIN,
+    reuseExistingServer: !process.env.CI,
+    timeout: 120_000,
+  },
+  projects: [{ name: 'chromium', use: { ...devices['Desktop Chrome'] } }],
+});