error response consistency, human readible1

packages/orchestration-service/src/routes/chat.js

@@ -20,7 +20,7 @@ router.post('/', async (req, res) => {
         res.json(result)
     } catch (err) {
         logger.error(`[orchestration] chat error: `, err.message)
-        res.status(500).json ({ error: err.message})
+        res.status(500).json ({ error: 'Chat failed', detail: err.message })
     }
 });