Add frontend speed test application and server setup

* Introduced a new HTML frontend for network speed testing with a responsive UI
* Implemented backend server functionality to serve the frontend and handle speed test APIs
* Added speed test logic for downloading and uploading data, including progress tracking and result validation
* Created README-SPEEDTEST.md for documentation on application architecture, setup, and usage.
* Updated package.json to include necessary scripts and dependencies for development and testing

serve-frontend.ts

@@ -0,0 +1,59 @@
+#!/usr/bin/env bun
+import { readFile } from 'fs/promises';
+import { LoggerFactory } from '@techniker-me/logger';
+
+const logger = LoggerFactory.getLogger('FrontendServer');
+
+const PORT = 3001;
+
+const server = Bun.serve({
+  port: PORT,
+  async fetch(request) {
+    const url = new URL(request.url);
+
+    // Serve the HTML frontend
+    if (url.pathname === '/' || url.pathname === '/index.html') {
+      try {
+        const html = await readFile('./frontend.html', 'utf-8');
+        return new Response(html, {
+          headers: {
+            'Content-Type': 'text/html',
+            'Cache-Control': 'no-cache'
+          }
+        });
+      } catch (error) {
+        logger.error('Failed to read frontend.html:', error);
+        return new Response('Frontend file not found', { status: 404 });
+      }
+    }
+
+    // Health check endpoint
+    if (url.pathname === '/health') {
+      return new Response(JSON.stringify({
+        status: 'ok',
+        frontend: 'serving',
+        speedtest_server: 'http://localhost:8080'
+      }), {
+        headers: { 'Content-Type': 'application/json' }
+      });
+    }
+
+    return new Response('Not found', { status: 404 });
+  }
+});
+
+logger.info(`Frontend server started on http://localhost:${PORT}`);
+logger.info(`Speedtest backend server expected on http://localhost:8080`);
+logger.info(`Open http://localhost:${PORT} in your browser to run the speed test`);
+
+process.on('SIGINT', () => {
+  logger.info('Shutting down frontend server...');
+  server.stop();
+  process.exit(0);
+});
+
+process.on('SIGTERM', () => {
+  logger.info('Shutting down frontend server...');
+  server.stop();
+  process.exit(0);
+});