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/execa/lib/kill.js

@@ -0,0 +1,115 @@
+'use strict';
+const os = require('os');
+const onExit = require('signal-exit');
+
+const DEFAULT_FORCE_KILL_TIMEOUT = 1000 * 5;
+
+// Monkey-patches `childProcess.kill()` to add `forceKillAfterTimeout` behavior
+const spawnedKill = (kill, signal = 'SIGTERM', options = {}) => {
+	const killResult = kill(signal);
+	setKillTimeout(kill, signal, options, killResult);
+	return killResult;
+};
+
+const setKillTimeout = (kill, signal, options, killResult) => {
+	if (!shouldForceKill(signal, options, killResult)) {
+		return;
+	}
+
+	const timeout = getForceKillAfterTimeout(options);
+	const t = setTimeout(() => {
+		kill('SIGKILL');
+	}, timeout);
+
+	// Guarded because there's no `.unref()` when `execa` is used in the renderer
+	// process in Electron. This cannot be tested since we don't run tests in
+	// Electron.
+	// istanbul ignore else
+	if (t.unref) {
+		t.unref();
+	}
+};
+
+const shouldForceKill = (signal, {forceKillAfterTimeout}, killResult) => {
+	return isSigterm(signal) && forceKillAfterTimeout !== false && killResult;
+};
+
+const isSigterm = signal => {
+	return signal === os.constants.signals.SIGTERM ||
+		(typeof signal === 'string' && signal.toUpperCase() === 'SIGTERM');
+};
+
+const getForceKillAfterTimeout = ({forceKillAfterTimeout = true}) => {
+	if (forceKillAfterTimeout === true) {
+		return DEFAULT_FORCE_KILL_TIMEOUT;
+	}
+
+	if (!Number.isFinite(forceKillAfterTimeout) || forceKillAfterTimeout < 0) {
+		throw new TypeError(`Expected the \`forceKillAfterTimeout\` option to be a non-negative integer, got \`${forceKillAfterTimeout}\` (${typeof forceKillAfterTimeout})`);
+	}
+
+	return forceKillAfterTimeout;
+};
+
+// `childProcess.cancel()`
+const spawnedCancel = (spawned, context) => {
+	const killResult = spawned.kill();
+
+	if (killResult) {
+		context.isCanceled = true;
+	}
+};
+
+const timeoutKill = (spawned, signal, reject) => {
+	spawned.kill(signal);
+	reject(Object.assign(new Error('Timed out'), {timedOut: true, signal}));
+};
+
+// `timeout` option handling
+const setupTimeout = (spawned, {timeout, killSignal = 'SIGTERM'}, spawnedPromise) => {
+	if (timeout === 0 || timeout === undefined) {
+		return spawnedPromise;
+	}
+
+	let timeoutId;
+	const timeoutPromise = new Promise((resolve, reject) => {
+		timeoutId = setTimeout(() => {
+			timeoutKill(spawned, killSignal, reject);
+		}, timeout);
+	});
+
+	const safeSpawnedPromise = spawnedPromise.finally(() => {
+		clearTimeout(timeoutId);
+	});
+
+	return Promise.race([timeoutPromise, safeSpawnedPromise]);
+};
+
+const validateTimeout = ({timeout}) => {
+	if (timeout !== undefined && (!Number.isFinite(timeout) || timeout < 0)) {
+		throw new TypeError(`Expected the \`timeout\` option to be a non-negative integer, got \`${timeout}\` (${typeof timeout})`);
+	}
+};
+
+// `cleanup` option handling
+const setExitHandler = async (spawned, {cleanup, detached}, timedPromise) => {
+	if (!cleanup || detached) {
+		return timedPromise;
+	}
+
+	const removeExitHandler = onExit(() => {
+		spawned.kill();
+	});
+
+	return timedPromise.finally(() => {
+		removeExitHandler();
+	});
+};
+
+module.exports = {
+	spawnedKill,
+	spawnedCancel,
+	setupTimeout,
+	validateTimeout,
+	setExitHandler
+};