Capitalize userName in CollaborationPopup for consistent display

app/src/components/templates/CollaborationPopup.tsx

@@ -142,7 +142,7 @@ const CollaborationPopup: React.FC<CollaborateProps> = ({
                 <div className="you-container">
                   <div className="your-name">
                     <div className="user-profile">{userName && userName[0].toUpperCase()}</div>
-                    {userName}
+                    {userName && userName.charAt(0).toUpperCase() + userName.slice(1).toLowerCase()}
                   </div>
                   <div className="indicater">you</div>
                 </div>