added read-only mode + visual improvements

pages/api/v1/migration/index.ts

@@ -30,6 +30,12 @@ export default async function users(req: NextApiRequest, res: NextApiResponse) {
         .status(data.status)
         .json(data.response);
   } else if (req.method === "POST") {
+    if (process.env.DEMO_MODE === "true")
+      return res.status(400).json({
+        response:
+          "This action is disabled because this is a read-only demo of Linkwarden.",
+      });
+
     const request: MigrationRequest = JSON.parse(req.body);
 
     let data;