feat: subgraph check extensions

[wilsonrivera]

@coderabbitai summary

Checklist

• [ ] I have discussed my proposed changes in an issue and have received approval to proceed.
• [x] I have followed the coding standards of the project.
• [ ] Tests or benchmarks have been added or updated.
• [x] Documentation has been updated on https://github.com/wundergraph/cosmo-docs.
• [x] I have read the Contributors Guide.