feat: conistent danger zone delete flow

lib/mv_web/live/user_live/show.ex

@@ -27,6 +27,7 @@ defmodule MvWeb.UserLive.Show do
   use MvWeb, :live_view
 
   import MvWeb.LiveHelpers, only: [current_actor: 1]
+  import MvWeb.ErrorHelpers, only: [format_ash_error: 1]
 
   @impl true
   def render(assigns) do
@@ -80,6 +81,37 @@ defmodule MvWeb.UserLive.Show do
           <% end %>
         </:item>
       </.list>
+
+      <%!-- Danger zone: canonical pattern (same as member show) --%>
+      <%= if can?(@current_user, :destroy, @user) and not Mv.Helpers.SystemActor.system_user?(@user) do %>
+        <section class="mt-8 mb-6" aria-labelledby="danger-zone-heading">
+          <h2 id="danger-zone-heading" class="text-lg font-semibold mb-3 text-error">
+            {gettext("Danger zone")}
+          </h2>
+          <div class="border border-base-300 rounded-lg p-4 bg-base-100">
+            <p class="text-base-content/70 mb-4">
+              {gettext(
+                "Deleting this user cannot be undone. The user account and any linked member association will be affected."
+              )}
+            </p>
+            <.button
+              variant="danger"
+              phx-click="delete"
+              phx-value-id={@user.id}
+              data-confirm={
+                gettext("Are you sure you want to delete the user %{email}? This action cannot be undone.",
+                  email: @user.email
+                )
+              }
+              data-testid="user-delete"
+              aria-label={gettext("Delete user %{email}", email: @user.email)}
+            >
+              <.icon name="hero-trash" class="size-4" />
+              {gettext("Delete user")}
+            </.button>
+          </div>
+        </section>
+      <% end %>
     </Layouts.app>
     """
   end
@@ -103,4 +135,39 @@ defmodule MvWeb.UserLive.Show do
        |> assign(:user, user)}
     end
   end
+
+  @impl true
+  def handle_event("delete", %{"id" => id}, socket) do
+    user = socket.assigns.user
+    actor = current_actor(socket)
+
+    if to_string(id) != to_string(user.id) do
+      {:noreply, put_flash(socket, :error, gettext("User not found"))}
+    else
+      if Mv.Helpers.SystemActor.system_user?(user) do
+        {:noreply,
+         put_flash(socket, :error, gettext("System user cannot be deleted."))}
+      else
+        case Ash.destroy(user, domain: Mv.Accounts, actor: actor) do
+          :ok ->
+            {:noreply,
+             socket
+             |> put_flash(:success, gettext("User deleted successfully"))
+             |> push_navigate(to: ~p"/users")}
+
+          {:error, %Ash.Error.Forbidden{}} ->
+            {:noreply,
+             put_flash(
+               socket,
+               :error,
+               gettext("You do not have permission to delete this user")
+             )}
+
+          {:error, error} ->
+            {:noreply,
+             put_flash(socket, :error, format_ash_error(error))}
+        end
+      end
+    end
+  end
 end