Scope managed Kura region hostnames per environment

Managed Kura regions now receive distinct public hostnames per environment. Staging and canary deployments add an environment suffix to the hostname (for example, acme-eu-central-1-staging.kura.tuist.dev), while production remains unchanged. This prevents staging and canary nodes from resolving to the same hostname as production, which previously caused cross-environment routing and left the staging or canary node unreachable. The change is automatically applied to already-provisioned nodes, and the corresponding cache endpoints are updated so the CLI resolves the correct regional node for each environment.