spec_html_export

The site static build exports the workspace requirement graph ( excluding `*.secret.rq` ) under `out/spec/` via `reqlan export`.
It must pass html_export_url_base for `/spec` ( honouring `SITE_BASE_PATH`, e. g. `/reqlan/spec` in production ) so `/spec` loads with or without a trailing slash.
It must pass html_export_header_link pointing at the marketing site home so readers can leave the embedded spec and return to the parent site.
Pipeline: build-static.mts → export-spec.mts → verify-static-export.mts.
Host options come from html_export / CLI commands.

Status: done

Interactive page: spec_html_export