feat: manage jellyfin data migration_flag

modules/libs/lib/facter/jellyfin_migration_done.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+require 'facter'
+
+Facter.add(:jellyfin_migration_done) do
+  setcode do
+    File.exist?('/etc/sysconfig/jellyfin_migration_done')
+  end
+end