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-reports/lib/json-summary/index.js

@@ -0,0 +1,56 @@
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+'use strict';
+const { ReportBase } = require('istanbul-lib-report');
+
+class JsonSummaryReport extends ReportBase {
+    constructor(opts) {
+        super();
+
+        this.file = opts.file || 'coverage-summary.json';
+        this.contentWriter = null;
+        this.first = true;
+    }
+
+    onStart(root, context) {
+        this.contentWriter = context.writer.writeFile(this.file);
+        this.contentWriter.write('{');
+    }
+
+    writeSummary(filePath, sc) {
+        const cw = this.contentWriter;
+        if (this.first) {
+            this.first = false;
+        } else {
+            cw.write(',');
+        }
+        cw.write(JSON.stringify(filePath));
+        cw.write(': ');
+        cw.write(JSON.stringify(sc));
+        cw.println('');
+    }
+
+    onSummary(node) {
+        if (!node.isRoot()) {
+            return;
+        }
+        this.writeSummary('total', node.getCoverageSummary());
+    }
+
+    onDetail(node) {
+        this.writeSummary(
+            node.getFileCoverage().path,
+            node.getCoverageSummary()
+        );
+    }
+
+    onEnd() {
+        const cw = this.contentWriter;
+        cw.println('}');
+        cw.close();
+    }
+}
+
+module.exports = JsonSummaryReport;