The substrate machines are now rendered from the live k3s nodes (arch, cpu,
memory, GPU, k3s version), read in-cluster via the mounted ServiceAccount with a
stdlib HTTP client (no client-go) and a 30s cache; falls back to the authored
substrate whenever the cluster is unreachable. Placement per the homelab decision
"in-cluster only for in-workload ops" — a running web app rendering live data fits.
HostsFromNodes parser built test-first. RBAC (read-only node-reader SA) shipped in
infra k3s/apps/cad-atlas/.
Verified: go build/vet/lint(0)/test green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
