[refactor] move rbm.label → label.label

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/tests/test_learn_norbs_labels.py

@@ -4,7 +4,7 @@ from rbm.model import Model
 from rbm.entity import Entity, EntityParams, TrainingParams
 from rbm.matrix import Mat, np, read_armadillo
 from rbm.train import train, Status
-from rbm.label import Label
+from label.label import Label
 
 class TestModel(Model):
 	def __init__(self, name: str, work_dir: str = '.'):