Update model_utils.py

model_utils.py

@@ -35,6 +35,8 @@ embed_model = SentenceTransformer(EMBED_MODEL_NAME)
 embed_model = embed_model.to(device)
 
 
+# NOTE: called once after load_curriculum() to precompute embeddings.
+# If you ever reload curriculum at runtime, call _build_entry_embeddings() again.
 def _build_entry_embeddings() -> None:
     """
     Build embeddings for each textbook entry using title + summary + text