Add OpenAI client fallback for MindVisualizer explanations

mindVisualizer/src/region_analyzer.py

@@ -93,6 +93,21 @@ def _call_direct_responses_api(question: str, model: str) -> str:
         "Be concrete, not generic."
     )
 
+    if not hasattr(client, "responses"):
+        # Older openai-python builds do not expose client.responses. Keep the
+        # deployed Space useful instead of failing with "'OpenAI' has no
+        # attribute 'responses'"; requirements should still install a newer SDK.
+        chat = client.chat.completions.create(
+            model=model,
+            messages=[
+                {"role": "system", "content": instructions},
+                {"role": "user", "content": question},
+            ],
+            temperature=0.3,
+            max_tokens=1500,
+        )
+        return (chat.choices[0].message.content or "").strip() or "[GPT ERROR] Chat API returned no visible text."
+
     resp = client.responses.create(
         model=model,
         instructions=instructions,