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/istanbul-lib-report/lib/report-base.js

@@ -0,0 +1,16 @@
+'use strict';
+
+// TODO: switch to class private field when targetting node.js 12
+const _summarizer = Symbol('ReportBase.#summarizer');
+
+class ReportBase {
+    constructor(opts = {}) {
+        this[_summarizer] = opts.summarizer;
+    }
+
+    execute(context) {
+        context.getTree(this[_summarizer]).visit(this, context);
+    }
+}
+
+module.exports = ReportBase;