Rebrand the guest page and host console as JohnFeed

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/static/guest.js

@@ -17,7 +17,7 @@ function note(msg){
 }
 function diagReport(){
   const head = [
-    'MMO Guest Line - what is happening',
+    'JohnFeed - what is happening',
     'copied ' + new Date().toString(),
     'browser: ' + navigator.userAgent,
     'name: ' + ($('#name').value.trim() || 'Guest') + ' | headphones ticked: ' + $('#headphones').checked,