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/src/components/views/login-view.tsx

@@ -67,6 +67,7 @@ export function LoginView() {
               disabled={isLoading}
               autoFocus
               className="font-mono"
+              data-testid="login-api-key-input"
             />
           </div>
 
@@ -77,7 +78,12 @@ export function LoginView() {
             </div>
           )}
 
-          <Button type="submit" className="w-full" disabled={isLoading || !apiKey.trim()}>
+          <Button
+            type="submit"
+            className="w-full"
+            disabled={isLoading || !apiKey.trim()}
+            data-testid="login-submit-button"
+          >
             {isLoading ? (
               <>
                 <Loader2 className="mr-2 h-4 w-4 animate-spin" />