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/@jest/expect/build/index.d.ts

@@ -0,0 +1,66 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {
+  AsymmetricMatchers,
+  BaseExpect,
+  Inverse,
+  MatcherContext,
+  MatcherFunction,
+  MatcherFunctionWithContext,
+  MatcherState,
+  MatcherUtils,
+  Matchers,
+} from 'expect';
+import {SnapshotMatchers, addSerializer} from 'jest-snapshot';
+
+export {AsymmetricMatchers};
+
+export declare type JestExpect = {
+  <T = unknown>(
+    actual: T,
+  ): JestMatchers<void, T> &
+    Inverse<JestMatchers<void, T>> &
+    PromiseMatchers<T>;
+  addSnapshotSerializer: typeof addSerializer;
+} & BaseExpect &
+  AsymmetricMatchers &
+  Inverse<Omit<AsymmetricMatchers, 'any' | 'anything'>>;
+
+export declare const jestExpect: JestExpect;
+
+declare type JestMatchers<R extends void | Promise<void>, T> = Matchers<R, T> &
+  SnapshotMatchers<R, T>;
+
+export {MatcherContext};
+
+export {MatcherFunction};
+
+export {MatcherFunctionWithContext};
+
+export {Matchers};
+
+export {MatcherState};
+
+export {MatcherUtils};
+
+declare type PromiseMatchers<T = unknown> = {
+  /**
+   * Unwraps the reason of a rejected promise so any other matcher can be chained.
+   * If the promise is fulfilled the assertion fails.
+   */
+  rejects: JestMatchers<Promise<void>, T> &
+    Inverse<JestMatchers<Promise<void>, T>>;
+  /**
+   * Unwraps the value of a fulfilled promise so any other matcher can be chained.
+   * If the promise is rejected the assertion fails.
+   */
+  resolves: JestMatchers<Promise<void>, T> &
+    Inverse<JestMatchers<Promise<void>, T>>;
+};
+
+export {};