Set up comprehensive frontend testing infrastructure

- Install Jest for unit testing with React Testing Library
- Install Playwright for end-to-end testing
- Configure Jest with proper TypeScript support and module mapping
- Create test setup files and utilities for both unit and e2e tests

Components:
* Jest configuration with coverage thresholds
* Playwright configuration with browser automation
* Unit tests for LoginForm, AuthContext, and useSocketIO hook
* E2E tests for authentication, dashboard, and agents workflows
* GitHub Actions workflow for automated testing
* Mock data and API utilities for consistent testing
* Test documentation with best practices

Testing features:
- Unit tests with 70% coverage threshold
- E2E tests with API mocking and user journey testing
- CI/CD integration for automated test runs
- Cross-browser testing support with Playwright
- Authentication system testing end-to-end

🚀 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/node_modules/@testing-library/user-event/dist/esm/utility/clear.js

@@ -0,0 +1,30 @@
+import '../event/behavior/click.js';
+import '../event/behavior/cut.js';
+import '../event/behavior/keydown.js';
+import '../event/behavior/keypress.js';
+import '../event/behavior/keyup.js';
+import '../event/behavior/paste.js';
+import '@testing-library/dom';
+import '../utils/dataTransfer/Clipboard.js';
+import { isEditable } from '../utils/edit/isEditable.js';
+import { isDisabled } from '../utils/misc/isDisabled.js';
+import { focusElement } from '../event/focus.js';
+import { input } from '../event/input.js';
+import { selectAll, isAllSelected } from '../event/selection/selectAll.js';
+
+async function clear(element) {
+    if (!isEditable(element) || isDisabled(element)) {
+        throw new Error('clear()` is only supported on editable elements.');
+    }
+    focusElement(element);
+    if (element.ownerDocument.activeElement !== element) {
+        throw new Error('The element to be cleared could not be focused.');
+    }
+    selectAll(element);
+    if (!isAllSelected(element)) {
+        throw new Error('The element content to be cleared could not be selected.');
+    }
+    input(this, element, '', 'deleteContentBackward');
+}
+
+export { clear };