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/cssstyle/lib/properties/padding.js

@@ -0,0 +1,58 @@
+"use strict";
+
+const parsers = require("../parsers");
+
+const positions = ["top", "right", "bottom", "left"];
+
+module.exports.parse = function parse(v) {
+  const val = parsers.parseMeasurement(v, true);
+  if (val) {
+    return val;
+  }
+  return parsers.parseKeyword(v);
+};
+
+module.exports.isValid = function isValid(v) {
+  if (v === "") {
+    return true;
+  }
+  return typeof module.exports.parse(v) === "string";
+};
+
+module.exports.definition = {
+  set(v) {
+    v = parsers.prepareValue(v, this._global);
+    if (parsers.hasVarFunc(v)) {
+      this._implicitSetter(
+        "padding",
+        "",
+        "",
+        module.exports.isValid,
+        module.exports.parse,
+        positions
+      );
+      this._setProperty("padding", v);
+    } else {
+      this._implicitSetter(
+        "padding",
+        "",
+        v,
+        module.exports.isValid,
+        module.exports.parse,
+        positions
+      );
+    }
+  },
+  get() {
+    const val = this._implicitGetter("padding", positions);
+    if (val === "") {
+      return this.getPropertyValue("padding");
+    }
+    if (parsers.hasVarFunc(val)) {
+      return "";
+    }
+    return val;
+  },
+  enumerable: true,
+  configurable: true
+};