feat: improve test setup and authentication handling

- Added `dev:test` script to package.json for streamlined testing without file watching.
- Introduced `kill-test-servers` script to ensure no existing servers are running on test ports before executing tests.
- Enhanced Playwright configuration to use mock agent for tests, ensuring consistent API responses and disabling rate limiting.
- Updated various test files to include authentication steps and handle login screens, improving reliability and reducing flakiness in tests.
- Added `global-setup` for e2e tests to ensure proper initialization before test execution.

apps/ui/tests/git/worktree-integration.spec.ts

@@ -13,6 +13,8 @@ import {
   createTempDirPath,
   setupProjectWithPath,
   waitForBoardView,
+  authenticateForTests,
+  handleLoginScreenIfPresent,
 } from '../utils';
 
 const TEST_TEMP_DIR = createTempDirPath('worktree-tests');
@@ -47,7 +49,10 @@ test.describe('Worktree Integration', () => {
 
   test('should display worktree selector with main branch', async ({ page }) => {
     await setupProjectWithPath(page, testRepo.path);
+    await authenticateForTests(page);
     await page.goto('/');
+    await page.waitForLoadState('load');
+    await handleLoginScreenIfPresent(page);
     await waitForNetworkIdle(page);
     await waitForBoardView(page);