[Code scan] Fix invalid dftio.data __all__ exports

[njzjz]

This issue comes from a Codex global repository scan.

Problem

dftio.data.__all__ contains imported objects instead of string names:

dftio/dftio/data/__init__.py

Lines 15 to 29 in c9d128f

	__all__ = [
	AtomicData,
	PBC,
	register_fields,
	deregister_fields,
	block_to_feature,
	feature_to_block,
	_register_field_prefix,
	feature_to_block,
	OrbitalMapper,
	_NODE_FIELDS,
	_EDGE_FIELDS,
	_GRAPH_FIELDS,
	_LONG_FIELDS,
	]

Python expects every __all__ entry to be a string. As written, wildcard imports fail instead of exporting the public API.

Reproduction

Run:

from dftio.data import *

This raises TypeError: Item in dftio.data.__all__ must be str.

Suggested fix

Change entries to string names and remove the duplicate feature_to_block entry.