Fix: Add missing generateTestId function causing server crash

lib/runner.js

@@ -1,6 +1,7 @@
 // lighthouse, chrome-launcher, uuid are ESM only/compatible, imported dynamically
 const fs = require('fs');
 const path = require('path');
+const crypto = require('crypto');
 
 // Simple Queue Implementation to prevent concurrency crashes
 class TestQueue {
@@ -265,6 +266,11 @@ async function getHistory(userUuid, userIp) {
   }
 }
 
+// Helper to generate distinct test IDs
+function generateTestId() {
+  return crypto.randomUUID();
+}
+
 // Need os for tmpdir
 const os = require('os');