When permalink_structure is empty, rest_url() is
index.php?rest_route=/aksrt/v1. Naive base+endpoint produced
rest_route=/aksrt/v1/banners?kind=banner (query inside route value),
so WP returned rest_no_route and Banner/Hero managers 404'd.
Fold path into rest_route and append extra params as siblings.
Make aksrt_settings the sole theme settings store for get_all(), remove
aksrt_seo_settings/aksrt_basic_settings merge paths, point global.logo
schema at aksrt_settings, and delete the retired settings migration page,
route, REST endpoint, and related SPA surface.