Gate sidebar menu items by can_access_page?

Members, Fee Types and Administration subitems only shown when user
has page permission. Add admin_menu_visible? helper. Sidebar test
uses admin user so menu items render.

test/mv_web/components/layouts/sidebar_test.exs

@@ -22,9 +22,14 @@ defmodule MvWeb.Layouts.SidebarTest do
   # =============================================================================
 
   # Returns assigns for an authenticated user with all required attributes.
+  # User has admin role so can_access_page? returns true for all sidebar links.
   defp authenticated_assigns(mobile \\ false) do
     %{
-      current_user: %{id: "user-123", email: "test@example.com"},
+      current_user: %{
+        id: "user-123",
+        email: "test@example.com",
+        role: %{permission_set_name: "admin"}
+      },
       club_name: "Test Club",
       mobile: mobile
     }