Parameterises the public-surface smoke test by host (one required input,
mapped via env: HOST). Keeps the three checks verbatim — login reachable,
HSTS value pinned, Permissions-Policy present, /actuator -> 404 — plus the
/proc/net/route gateway-detection and RESOLVE-array rationale.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
