Heterogeneous Fleet Onboarding

A fleet can contain macOS hosts, Linux PCs, ARM systems, and init-less pods. Uniformity comes from contracts and evidence rather than identical operating systems. The registry records targets and roles; deployment discovers the supervisor, architecture, filesystem, container runtime, and available coding CLIs on each selected node.

Hosts are provisioned by hand from the "Provision a new host" checklist in Updating the fleet with fleet-update, then moved to a commit with scripts/fleet-update. Targets come from the fleet inventory, ~/.mac/fleets.yaml; mac admin fleet inventory prints it.

test -x "$DOCS_ROOT/scripts/fleet-update"
python3 "$DOCS_ROOT/scripts/image-publication-identity.py" --help >/dev/null
test -f "$DOCS_ROOT/docs/operations/fleet-update.md"
test -f "$DOCS_ROOT/docs/fleet-registry-schema.md"

Onboarding is complete only when registry identity, route, credentials, the host's reported source commit, runtime attestation and a role-specific acceptance task all pass. Registration alone is not readiness.