Add model_module stub for checkpoint unpickling

src/recipe/phone_recognition/model_module.py

@@ -0,0 +1,12 @@
+"""Stub for checkpoint unpickling. The real class needs Lightning;
+this minimal version lets torch.load resolve pickled references."""
+
+import torch.nn as nn
+
+
+def get_w2v2ph_schedule(*args, **kwargs):
+    pass
+
+
+class PhoneRecognitionModel(nn.Module):
+    pass