fix(agent): /api/agent/run defaults to live when OPENROUTER_API_KEY is configured (was always mock)

app/api.py

@@ -633,7 +633,9 @@ def create_app(db_path, img_dir, state_dir=None):
 
     @app.post('/api/agent/run')
     def agent_run(body: dict):
-        source = body.get('source', 'mock') if isinstance(body, dict) else 'mock'
+        source = body.get('source') if isinstance(body, dict) else None
+        if source is None:
+            source = 'live' if live_configured() else 'mock'
         if source not in ('mock', 'live'):
             raise HTTPException(status_code=400,
                                 detail='source must be mock|live')