docs(api): hide models sidebar in Scalar reference (#3459)

Pass `hideModels: true` to the Scalar apiReference middleware so the
public `/api/docs` no longer exposes the internal Models tree
(Mongoose-derived shapes, error envelopes, intermediate DTOs). Schemas
are still documented inline on each endpoint — the Models section just
leaks implementation detail without helping API consumers.

Stack-side default — every downstream project benefits without extra
config.

Closes #3458

Author: PierreBrisorgueil

lib/services/express.js

@@ -92,6 +92,7 @@ const initSwagger = (app) => {
       '/api/docs',
       apiReference({
         spec: { content: spec },
+        hideModels: true,
       }),
     );
   }