Add rack placement frontmatter to mf00–mf04, fix pre-existing schema
error in docs/services/coursemanagement.md (missing kind/name fields),
extend Makefile docs-index and docs-check targets to also run gen_rack,
add test target, generate rack01.md and rack01-elevation.svg.
Positions are provisional placeholders to prove the pipeline; correct when mounting.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
