Fix QR data handling in WhatsApp auth (#467)

Running WhatsApp setup fails because the string interpolation of `qrData` does not inject quotes.

setup/whatsapp-auth.ts

@@ -210,7 +210,7 @@ async function handleQrBrowser(
   const qrData = fs.readFileSync(qrFile, 'utf-8');
   try {
     const svg = execSync(
-      `node -e "const QR=require('qrcode');const data=${JSON.stringify(qrData)};QR.toString(data,{type:'svg'},(e,s)=>{if(e)process.exit(1);process.stdout.write(s)})"`,
+      `node -e "const QR=require('qrcode');const data='${qrData}';QR.toString(data,{type:'svg'},(e,s)=>{if(e)process.exit(1);process.stdout.write(s)})"`,
       { cwd: projectRoot, encoding: 'utf-8' },
     );
     const html = QR_AUTH_TEMPLATE.replace('{{QR_SVG}}', svg);