feat: assign admin role to admin user in seeds

- Create Admin role if it doesn't exist
- Assign Admin role to admin@mv.local user
- Remove separate create_admin_role script (integrated into seeds)

lib/mv_web/live/role_live/index.ex

@@ -28,9 +28,20 @@ defmodule MvWeb.RoleLive.Index do
         # Load role if not already loaded (check for Ash.NotLoaded struct)
         user_with_role =
           case Map.get(user, :role) do
-            %Ash.NotLoaded{} -> Ash.load!(user, :role, domain: Mv.Accounts)
-            nil -> Ash.load!(user, :role, domain: Mv.Accounts)
-            role when not is_nil(role) -> user
+            %Ash.NotLoaded{} ->
+              case Ash.load(user, :role, domain: Mv.Accounts) do
+                {:ok, loaded_user} -> loaded_user
+                {:error, _} -> user
+              end
+
+            nil ->
+              case Ash.load(user, :role, domain: Mv.Accounts) do
+                {:ok, loaded_user} -> loaded_user
+                {:error, _} -> user
+              end
+
+            role when not is_nil(role) ->
+              user
           end
 
         assign(socket, :current_user, user_with_role)