feat: initial Speedboard implementation

sitespeed.io web UI with Express/Pug/SQLite — port 3132.
Includes job queue, SSE live log, full metrics dashboard,
site history, CO2/axe/CWV sections, and Docker support.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

routes/index.js

@@ -0,0 +1,11 @@
+import { Router } from 'express';
+const router = Router();
+
+router.get('/', (req, res) => {
+  res.render('index', {
+    title: 'Speedboard — Test a URL',
+    prefillUrl: req.query.url || '',
+  });
+});
+
+export default router;