Add chat debug logging

app.py

@@ -388,6 +388,10 @@ def phox_chat(message, history):
         return "Ring buffer full. Try again."
 
     pred_ids = poll_predictions()
+    # Debug: log what we got
+    import os
+    with open("/tmp/chat_debug.log", "a") as f:
+        f.write(f"Input tokens: {token_ids}, Output tokens: {pred_ids}\n")
     if not pred_ids:
         return "No prediction received (timeout). Try again."