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/rrweb-cssom/lib/MatcherList.js

@@ -0,0 +1,62 @@
+//.CommonJS
+var CSSOM = {};
+///CommonJS
+
+
+/**
+ * @constructor
+ * @see https://developer.mozilla.org/en/CSS/@-moz-document
+ */
+CSSOM.MatcherList = function MatcherList(){
+    this.length = 0;
+};
+
+CSSOM.MatcherList.prototype = {
+
+    constructor: CSSOM.MatcherList,
+
+    /**
+     * @return {string}
+     */
+    get matcherText() {
+        return Array.prototype.join.call(this, ", ");
+    },
+
+    /**
+     * @param {string} value
+     */
+    set matcherText(value) {
+        // just a temporary solution, actually it may be wrong by just split the value with ',', because a url can include ','.
+        var values = value.split(",");
+        var length = this.length = values.length;
+        for (var i=0; i<length; i++) {
+            this[i] = values[i].trim();
+        }
+    },
+
+    /**
+     * @param {string} matcher
+     */
+    appendMatcher: function(matcher) {
+        if (Array.prototype.indexOf.call(this, matcher) === -1) {
+            this[this.length] = matcher;
+            this.length++;
+        }
+    },
+
+    /**
+     * @param {string} matcher
+     */
+    deleteMatcher: function(matcher) {
+        var index = Array.prototype.indexOf.call(this, matcher);
+        if (index !== -1) {
+            Array.prototype.splice.call(this, index, 1);
+        }
+    }
+
+};
+
+
+//.CommonJS
+exports.MatcherList = CSSOM.MatcherList;
+///CommonJS