feat(chat): show username using preload

lib/slax_web/live/chat_room_live.ex

@@ -47,7 +47,7 @@ defmodule SlaxWeb.ChatRoomLive do
         <ul class="relative z-10 flex items-center gap-4 px-4 sm:px-6 lg:px-8 justify-end">
           <%= if @current_user do %>
             <li class="text-[0.8125rem] leading-6 text-zinc-900">
-              <%= @current_user.email %>
+              <%= username(@current_user) %>
             </li>
             <li>
               <.link
@@ -157,7 +157,7 @@ defmodule SlaxWeb.ChatRoomLive do
       <div class="ml-2">
         <div class="-mt-1">
           <.link class="text-sm font-semibold hover:underline">
-            <span>User</span>
+            <span><%= username(@message.user) %></span>
           </.link>
           <p class="text-sm"><%= @message.body %></p>
         </div>
@@ -165,4 +165,8 @@ defmodule SlaxWeb.ChatRoomLive do
     </div>
     """
   end
+
+  defp username(user) do
+    user.email |> String.split("@") |> List.first() |> String.capitalize()
+  end
 end