core: add helper to 'freeze' dataclasses, in order to derive a schema from the properties

my/core/cachew.py

@@ -1,11 +1,9 @@
+from .common import assert_subpackage; assert_subpackage(__name__)
+
 from contextlib import contextmanager
 from pathlib import Path
 from typing import Optional
 
-# can lead to some unexpected issues if you 'import cachew' which being in my/core directory.. so let's protect against it
-# NOTE: if we use overlay, name can be smth like my.origg.my.core.cachew ...
-assert 'my.core' in __name__, f'Expected module __name__ ({__name__}) to start with my.core'
-
 def disable_cachew() -> None:
     try:
         import cachew