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/diff-sequences/build/index.d.ts

@@ -0,0 +1,39 @@
+/**
+ * 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.
+ */
+
+export declare type Callbacks = {
+  foundSubsequence: FoundSubsequence;
+  isCommon: IsCommon;
+};
+
+declare function diffSequence(
+  aLength: number,
+  bLength: number,
+  isCommon: IsCommon,
+  foundSubsequence: FoundSubsequence,
+): void;
+export default diffSequence;
+
+declare type FoundSubsequence = (
+  nCommon: number, // caller can assume: 0 < nCommon
+  aCommon: number, // caller can assume: 0 <= aCommon && aCommon < aLength
+  bCommon: number,
+) => void;
+
+/**
+ * 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.
+ *
+ */
+declare type IsCommon = (
+  aIndex: number, // caller can assume: 0 <= aIndex && aIndex < aLength
+  bIndex: number,
+) => boolean;
+
+export {};