fix: make FSDP2 executor work with ABC+Generic model hierarchy

- Wrap each child module individually, skip root (CPython layout
  conflict between ABC+Generic and FSDP2 __class__ assignment)
- Remove manual unshard in clip_grad_norm (DTensor compatible)
- Fix _no_sync to iterate modules() instead of checking root
- Add reshard after unwrap_model
- Guard __init_subclass__ type resolution against dynamic subclasses
- Add fsdp2 to --parallel_mode CLI choices

astrai/factory.py

@@ -67,7 +67,10 @@ class BaseFactory(ABC, Generic[T]):
             if _get_origin(orig_base) is BaseFactory:
                 (arg,) = _get_args(orig_base)
                 cls._entries = {}
-                cls._component_base = _resolve_type(arg, cls)
+                try:
+                    cls._component_base = _resolve_type(arg, cls)
+                except Exception:
+                    cls._component_base = None
                 return
 
     @classmethod