[Mock API] Migrate commongrants.org name servers to Cloudflare

[laurabelinfante]

Summary

Move DNS name servers for commongrants.org from Namecheap to Cloudflare so the mock API can use custom subdomain routing (for example mock.commongrants.org) and root domain hosting, needed under either hosting option. Coordinate with IT on the migration.

Acceptance criteria

• commongrants.org name servers are migrated to Cloudflare
• The site works as before after the migration