Node 0 is the bootstrap host and therefore must be part of the control plane. This is selected automatically when the host is identified as the bootstrap.

With the UI available, we must prevent the user from changing the role for the bootstrap host back to either "worker" or "auto-assigned".

Reproduction steps:
1. In agentconfig have nodeA IP be the same as rendezvousIP
2. In agentconfig have nodeA role be set as worker
3. Generate ISO

Expected result:
ISO generation errors out pointing that rendezvousIP has to match a worker node

Actual result:
Image is generated

Other considerations:
For a purely DHCP environment, this has to be blocked at runtime by the API.