prevent double-click on create backup button

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/berrypod_web/live/admin/backup.ex

@@ -40,18 +40,25 @@ defmodule BerrypodWeb.Admin.Backup do
   end
 
   def handle_event("create_backup", _params, socket) do
-    case Backup.create_backup() do
-      {:ok, _path} ->
-        {:noreply,
-         socket
-         |> assign(:backups, Backup.list_backups())
-         |> assign(:create_backup_status, :saved)}
+    # Ignore if already creating
+    if socket.assigns.create_backup_status == :saving do
+      {:noreply, socket}
+    else
+      socket = assign(socket, :create_backup_status, :saving)
 
-      {:error, error} ->
-        {:noreply,
-         socket
-         |> assign(:create_backup_status, :error)
-         |> put_flash(:error, "Failed to create backup: #{inspect(error)}")}
+      case Backup.create_backup() do
+        {:ok, _path} ->
+          {:noreply,
+           socket
+           |> assign(:backups, Backup.list_backups())
+           |> assign(:create_backup_status, :saved)}
+
+        {:error, error} ->
+          {:noreply,
+           socket
+           |> assign(:create_backup_status, :error)
+           |> put_flash(:error, "Failed to create backup: #{inspect(error)}")}
+      end
     end
   end
 
@@ -323,6 +330,7 @@ defmodule BerrypodWeb.Admin.Backup do
               type="button"
               phx-click="create_backup"
               class="admin-btn admin-btn-primary admin-btn-sm"
+              disabled={@create_backup_status == :saving}
             >
               <.icon name="hero-plus-mini" class="size-4" /> Create backup
             </button>