Allow the admin Studio to browse and import furniture from custom retro hotel sources, not just official Habbo furnidata. - GET /api/admin/import/furni?source=<id> lists a clone source's furnidata (via getCloneList) and returns a per-item iconUrl from the source's iconBaseUrl so previews render correctly - Studio client gets a source selector dropdown (official Habbo plus all configured clone_sources) that resets the selection and reloads the list when switched - Single and batch imports now send sourceId so SWF/nitro/icon assets are fetched from the selected hotel's CDN - Preview images prefer the source iconUrl with the existing fallback chain; header shows the active source name