system prompt backend

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

@@ -73,6 +73,13 @@ if (req.body.topK !== undefined) {
   updates.topK = val;
 }
 
+if (req.body.systemPrompt !== undefined) {
+  const val = req.body.systemPrompt;
+  if (typeof val !== 'string') 
+    return res.status(400).json({ error: 'systemPrompt must be a string' });
+  updates.systemPrompt = val.trim() || null; // null reverts to default
+}
+
   res.json(settings.save(updates));
 });