feat(cli): move user and guild registration from API to local CLI

src/common/center-api-key.guard.ts

@@ -33,11 +33,6 @@ export class CenterApiKeyGuard implements CanActivate {
       return true;
     }
 
-    // only guild registration is exempt from API key; it is protected by HMAC secret
-    if (method === 'POST' && (path === '/nodes/register' || path.endsWith('/nodes/register'))) {
-      return true;
-    }
-
     const received = req.headers['x-api-key'];
     const apiKey = Array.isArray(received) ? received[0] : received;
     if (!apiKey) throw new UnauthorizedException('missing api key');