Update README.md

README.md

@@ -63,7 +63,17 @@ from langchain_community.document_loaders import PyPDFLoader
 2. Modified prompt format — slight improvement
 3. Switched to FLAN-T5-XL — OOM error
 
-**Final Solution:** Switched to Zephyr-7B-beta, which produces comprehensive answers.
+**Solution:** Switched to Zephyr-7B-beta, which produces comprehensive answers.
+
+### Challenge 4: Hugging Face Spaces Python 3.13 Migration
+**Problem:** Space failed on startup with `ModuleNotFoundError: No module named 'audioop'`
+**Cause:** Hugging Face Spaces updated to Python 3.13, which removed the deprecated `audioop` module from the standard library. Gradio 4.x depended on `pydub`, which required `audioop`.
+**Solution:** Upgraded to Gradio 6.3.0, which includes Python 3.13 compatibility fixes.
+
+### Challenge 5: Inference API Changes
+**Problem:** `InferenceClient.text_generation()` failed with "task not supported" error.
+**Cause:** The Hugging Face Inference API routing changed, requiring conversational models to use the `chat_completion` endpoint.
+**Solution:** Refactored from raw prompt templates to the structured `chat_completion()` API with message arrays.
 
 ## 📝 Limitations