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/ts-jest/dist/utils/json.js

@@ -0,0 +1,16 @@
+"use strict";
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.stringify = stringify;
+exports.parse = parse;
+const fast_json_stable_stringify_1 = __importDefault(require("fast-json-stable-stringify"));
+const UNDEFINED = 'undefined';
+function stringify(input) {
+    return input === undefined ? UNDEFINED : (0, fast_json_stable_stringify_1.default)(input);
+}
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function parse(input) {
+    return input === UNDEFINED ? undefined : JSON.parse(input);
+}