Simplify return payload of /auth.

Return only `.token` instead of `.session.token`.

frontend/src/mixins/api/Auth.vue

@@ -11,7 +11,7 @@ export default {
         body: payload
       })
 
-      return response?.session?.token;
+      return response?.token;
     },
 
     async logout(): Promise<any> {

src/routes/api/v1/Auth.ts

@@ -55,9 +55,7 @@ class Auth extends ApiV1Route {
     });
 
     res.json({
-      session: {
-        token: session.getToken(),
-      }
+      token: session.getToken(),
     });
   }