[Enhancement] Add setting to restrict filenames to ASCII characters (#660)

* Added a new column for restricting filenames

* Adds restrict-filenames to command runner

* Added UI to settings form

priv/repo/migrations/20250317213740_add_restrict_filenames_to_settings.exs

@@ -0,0 +1,9 @@
+defmodule Pinchflat.Repo.Migrations.AddRestrictFilenamesToSettings do
+  use Ecto.Migration
+
+  def change do
+    alter table(:settings) do
+      add :restrict_filenames, :boolean, default: false
+    end
+  end
+end