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/@testing-library/user-event/dist/cjs/utility/upload.js

@@ -0,0 +1,62 @@
+'use strict';
+
+var isElementType = require('../utils/misc/isElementType.js');
+var FileList = require('../utils/dataTransfer/FileList.js');
+require('../utils/dataTransfer/Clipboard.js');
+var setFiles = require('../utils/edit/setFiles.js');
+var isDisabled = require('../utils/misc/isDisabled.js');
+var getWindow = require('../utils/misc/getWindow.js');
+
+async function upload(element, fileOrFiles) {
+    const input = isElementType.isElementType(element, 'label') ? element.control : element;
+    if (!input || !isElementType.isElementType(input, 'input', {
+        type: 'file'
+    })) {
+        throw new TypeError(`The ${input === element ? 'given' : 'associated'} ${input === null || input === undefined ? undefined : input.tagName} element does not accept file uploads`);
+    }
+    if (isDisabled.isDisabled(element)) return;
+    const files = (Array.isArray(fileOrFiles) ? fileOrFiles : [
+        fileOrFiles
+    ]).filter((file)=>!this.config.applyAccept || isAcceptableFile(file, input.accept)).slice(0, input.multiple ? undefined : 1);
+    const fileDialog = ()=>{
+        var _input_files;
+        // do not fire an input event if the file selection does not change
+        if (files.length === ((_input_files = input.files) === null || _input_files === undefined ? undefined : _input_files.length) && files.every((f, i)=>{
+            var _input_files;
+            return f === ((_input_files = input.files) === null || _input_files === undefined ? undefined : _input_files.item(i));
+        })) {
+            return;
+        }
+        setFiles.setFiles(input, FileList.createFileList(getWindow.getWindow(element), files));
+        this.dispatchUIEvent(input, 'input');
+        this.dispatchUIEvent(input, 'change');
+    };
+    input.addEventListener('fileDialog', fileDialog);
+    await this.click(element);
+    input.removeEventListener('fileDialog', fileDialog);
+}
+// When matching files, browsers ignore case and consider jpeg/jpg interchangeable.
+function normalize(nameOrType) {
+    return nameOrType.toLowerCase().replace(/(\.|\/)jpg\b/g, '$1jpeg');
+}
+function isAcceptableFile(file, accept) {
+    if (!accept) {
+        return true;
+    }
+    const wildcards = [
+        'audio/*',
+        'image/*',
+        'video/*'
+    ];
+    return normalize(accept).trim().split(/\s*,\s*/).some((acceptToken)=>{
+        // tokens starting with a dot represent a file extension
+        if (acceptToken.startsWith('.')) {
+            return normalize(file.name).endsWith(acceptToken);
+        } else if (wildcards.includes(acceptToken)) {
+            return normalize(file.type).startsWith(acceptToken.replace('*', ''));
+        }
+        return normalize(file.type) === acceptToken;
+    });
+}
+
+exports.upload = upload;