[Code scan] Fix ABACUS Gamma add_fix attribute typo

[njzjz]

This issue is from a Codex global scan of the repository.

ABACUS Gamma post-processing uses a misspelled attribute and fails when add_fix is enabled.

Evidence:

dpgen/dpgen/auto_test/Gamma.py

Lines 370 to 373 in 7af5246

	def __stru_fix(self, stru) -> None:
	fix_dict = {"true": True, "false": False}
	fix_xyz = [fix_dict[i] for i in self.addfix]
	abacus.stru_fix_atom(stru, fix_atom=fix_xyz)

dpgen/dpgen/auto_test/Gamma.py

Lines 405 to 416 in 7af5246

	def post_process(self, task_list):
	if self.add_fix:
	count = 0
	for ii in task_list:
	count += 1
	inter = os.path.join(ii, "inter.json")
	poscar = os.path.join(ii, "POSCAR")
	calc_type = loadfn(inter)["type"]
	if calc_type == "vasp":
	self.__poscar_fix(poscar)
	elif calc_type == "abacus":
	self.__stru_fix(os.path.join(ii, "STRU"))

post_process() checks self.add_fix and dispatches ABACUS tasks to __stru_fix(), but __stru_fix() reads self.addfix without the underscore. That attribute is not defined by the surrounding code, so ABACUS Gamma tasks with fixed directions raise AttributeError before calling abacus.stru_fix_atom().

Expected behavior: __stru_fix() should use the same self.add_fix attribute used by the VASP and LAMMPS fix paths.