Remove __hello_only__.py source file and its symlink. Register
__hello_only__ as a frozen module alias reusing __hello__ bytecode,
matching the behavior where origname is None (no source file).
* Fix test_import: import machinery and errors
- Emit IMPORT_FROM instead of LOAD_ATTR for `import a.b.c as m`
- Add "partially initialized module" error for circular imports
- Add "cannot access submodule" error for initializing submodules
- Implement script shadowing detection with "consider renaming" hint
- Detect user scripts shadowing stdlib/third-party modules
- Compute original sys.path[0] from sys.argv[0]
- Check sys.stdlib_module_names for stdlib detection
- Respect safe_path setting
- Implement _imp._fix_co_filename for code source_path rewriting
- Add data parameter to _imp.get_frozen_object with marshal deser
- Fix import_from: check __spec__.has_location before using origin
- Set ImportError.path attribute on import failures
- Fix import_star error messages for non-str __all__/__dict__ items
- Always call builtins.__import__ in import_inner
* Propagate __bool__ errors from fromlist in import
Previously, try_to_bool errors were silently swallowed via .ok(),
causing fromlist with broken __bool__ to default to false.
