Warehouse-location settings page (/admin/settings/warehouse).

Extracted from the warehouse section of Andi's /admin/settings/andi page (lib/andi_web/live/admin/settings/andi.ex) — which location type marks warehouses and which location is the default warehouse for stock. Both persist to PhoenixKit.Settings (admin-configurable, no redeploy) via PhoenixKitWarehouse.StockLedger.

Admin header-breadcrumb pattern: use PhoenixKitWeb, :live_view + a self_wrapped_layout on_mount wrapping render/1 in <LayoutWrapper.app_layout> (title in the global admin header).