Function component for the "Customize columns" modal used by Manufacturing's admin list LiveViews.

Layout: two columns inside the modal.

• Selected (left) — drag to reorder. Each row also exposes a filter toggle for filterable columns; toggled state persists alongside column order.
• Available (right) — click to add.

The host LiveView must implement these handle_event/3 callbacks (provided by PhoenixKitManufacturing.Web.ColumnManagement):

• "hide_column_modal"
• "add_column" (%{"column_id" => id})
• "remove_column" (%{"column_id" => id})
• "toggle_filter" (%{"column_id" => id})
• "reorder_selected_columns" (%{"ordered_ids" => [...]})
• "update_table_columns" (form submit, %{"column_order" => csv})
• "reset_to_defaults"

This is a 1:1 adaptation of PhoenixKitWarehouse.Web.Components.ColumnModal — same markup and event contract, only the module namespace and Gettext backend changed. DraggableList is core's PhoenixKitWeb.Components.Core.DraggableList — no extra dependency needed.