GET /proxmox/api/{server_id}/images/node-arch derives amd64/arm64 from
node status current-kernel.machine; returns null when node unreachable.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
GET/POST/PUT/DELETE /proxmox/api/images/mirrors (perm template:manage).
Enabled mirrors merge into the catalog feed automatically.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>