fix: show actual config values in preview mode response

app.py

@@ -507,10 +507,14 @@ class SpaceGenerator:
                             f"Get your API key at: https://openrouter.ai/keys"
                         )
                     else:
-                        # Preview mode response
+                        # Show actual configuration being used
                         response = (
-                            f"[Preview Mode] This would call {config.get('model', 'Unknown')} "
-                            f"with your message: '{message}'"
+                            f"[Preview Mode - Configuration Active]\n\n"
+                            f"**Model:** {config.get('model', 'Unknown')}\n"
+                            f"**Temperature:** {config.get('temperature', 0.7)}\n"
+                            f"**Max Tokens:** {config.get('max_tokens', 750)}\n"
+                            f"**API Key Variable:** {config.get('api_key_var', 'Not set')}\n\n"
+                            f"In the deployed space, this configuration will be used to generate actual responses."
                         )
                     
                     # Update chat history