refactor: flatten src/AKSRT → src (drop theme-identifier dir)

Move all domain folders from src/AKSRT/{Domain} to src/{Domain}; remap
Composer PSR-4 "AKSRT\\": "src/"; update audit script + README + ADR
paths; remove dead tools/build-psr4-map.php (scanned deleted inc/classes).

composer.json

@@ -17,7 +17,7 @@
     },
     "autoload": {
         "psr-4": {
-            "AKSRT\\": "src/AKSRT/"
+            "AKSRT\\": "src/"
         }
     }
 }