SchemaProvider still mapped domains to pre-PSR-4 Schema\* strings, so REST
schema loads fatalled with Class Schema\GlobalSchema not found. Point the
builder map at AKSRT\Admin\Schema\* via ::class.
Move 288 types from global AKSRT_* + inc/classes manual requires into
namespace AKSRT\{Domain} under src/AKSRT/, wire composer.json psr-4,
and slim bootstrap to helpers/modules/hooks only. Split multi-class
widget/gateway files, update admin contract audit paths, and document
the layout in ADR/README.
kate522