Accept Proxmox API endpoints with or without /api2/json in CI and local
tfvars, and avoid running the dashboards workflow just because its own
workflow file changed during platform migrations.
Replace Hetzner infrastructure and cloud-provider assumptions with Proxmox
VM clones, kube-vip API HA, and NFS-backed storage. Update bootstrap,
Flux addons, CI workflows, and docs to target the new private Proxmox
baseline while preserving the existing Tailscale, Doppler, Flux, Rancher,
and B2 backup flows.