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/pretty-format/build/plugins/DOMElement.js

@@ -0,0 +1,128 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', {
+  value: true
+});
+exports.test = exports.serialize = exports.default = void 0;
+
+var _markup = require('./lib/markup');
+
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+const ELEMENT_NODE = 1;
+const TEXT_NODE = 3;
+const COMMENT_NODE = 8;
+const FRAGMENT_NODE = 11;
+const ELEMENT_REGEXP = /^((HTML|SVG)\w*)?Element$/;
+
+const testHasAttribute = val => {
+  try {
+    return typeof val.hasAttribute === 'function' && val.hasAttribute('is');
+  } catch {
+    return false;
+  }
+};
+
+const testNode = val => {
+  const constructorName = val.constructor.name;
+  const {nodeType, tagName} = val;
+  const isCustomElement =
+    (typeof tagName === 'string' && tagName.includes('-')) ||
+    testHasAttribute(val);
+  return (
+    (nodeType === ELEMENT_NODE &&
+      (ELEMENT_REGEXP.test(constructorName) || isCustomElement)) ||
+    (nodeType === TEXT_NODE && constructorName === 'Text') ||
+    (nodeType === COMMENT_NODE && constructorName === 'Comment') ||
+    (nodeType === FRAGMENT_NODE && constructorName === 'DocumentFragment')
+  );
+};
+
+const test = val => {
+  var _val$constructor;
+
+  return (
+    (val === null || val === void 0
+      ? void 0
+      : (_val$constructor = val.constructor) === null ||
+        _val$constructor === void 0
+      ? void 0
+      : _val$constructor.name) && testNode(val)
+  );
+};
+
+exports.test = test;
+
+function nodeIsText(node) {
+  return node.nodeType === TEXT_NODE;
+}
+
+function nodeIsComment(node) {
+  return node.nodeType === COMMENT_NODE;
+}
+
+function nodeIsFragment(node) {
+  return node.nodeType === FRAGMENT_NODE;
+}
+
+const serialize = (node, config, indentation, depth, refs, printer) => {
+  if (nodeIsText(node)) {
+    return (0, _markup.printText)(node.data, config);
+  }
+
+  if (nodeIsComment(node)) {
+    return (0, _markup.printComment)(node.data, config);
+  }
+
+  const type = nodeIsFragment(node)
+    ? 'DocumentFragment'
+    : node.tagName.toLowerCase();
+
+  if (++depth > config.maxDepth) {
+    return (0, _markup.printElementAsLeaf)(type, config);
+  }
+
+  return (0, _markup.printElement)(
+    type,
+    (0, _markup.printProps)(
+      nodeIsFragment(node)
+        ? []
+        : Array.from(node.attributes)
+            .map(attr => attr.name)
+            .sort(),
+      nodeIsFragment(node)
+        ? {}
+        : Array.from(node.attributes).reduce((props, attribute) => {
+            props[attribute.name] = attribute.value;
+            return props;
+          }, {}),
+      config,
+      indentation + config.indent,
+      depth,
+      refs,
+      printer
+    ),
+    (0, _markup.printChildren)(
+      Array.prototype.slice.call(node.childNodes || node.children),
+      config,
+      indentation + config.indent,
+      depth,
+      refs,
+      printer
+    ),
+    config,
+    indentation
+  );
+};
+
+exports.serialize = serialize;
+const plugin = {
+  serialize,
+  test
+};
+var _default = plugin;
+exports.default = _default;