[quality] docs/ and blog/ MDX component imports and CNCFProjectCard props have no unit coverage #297

Finding

Nothing in tests/ reads a docs/ or blog/ file's MDX component imports or
JSX props. grep -rln '@site' tests/ and grep -rln 'blog/' tests/ both return
nothing at rev 00b44df.

Two distinct gaps sit behind that:

1. Component imports are verified only by a full site build.
docs/ carries 8 @site/src/components/... imports and 9 distinct capitalized
JSX tags. .github/workflows/ci.yml runs npm run build:production on every
PR, so an un-imported tag or a moved component directory is caught — but late,
as a Docusaurus/webpack error wall rather than a named assertion, and only after
npm ci plus a full production build. Any refactor that moves a component
directory (for example splitting MemberDirectory) breaks a docs import with no
fast signal.

2. Misspelled <CNCFProjectCard> props are caught by nothing at all.
docs/architectures/*.md contains 50 hand-authored <CNCFProjectCard />
usages. src/components/CNCFProjectCard/index.js destructures a fixed prop
set (name, logo, href, since, version, description). MDX passes
unknown props straight through, so descripton="..." or url="..." is dropped
silently: the card renders without the text or the link, the production build
stays green, and no validator reports it. This is covered by neither unit nor
end-to-end tests.

name is also dereferenced unconditionally (name.slice(0, 1) in the fallback
logo branch) and href is the card's only navigation target, so neither has a
usable default.

Recommendation

Add tests/mdx-components.test.mjs — a test-only file using nothing but
node:test, node:assert/strict, node:fs and node:path — asserting over
every docs/**/*.md{,x} and blog/**/*.md{,x}:

• every capitalized JSX tag used in a file is imported in that same file
• every @site/ import specifier resolves to a file on disk
• every <CNCFProjectCard /> supplies name and href
• no <CNCFProjectCard /> passes a prop the component does not destructure,
  with the accepted set parsed out of the component so a rename there cannot
  silently diverge from the 50 usages
• the scan is non-empty, so the assertions cannot pass vacuously

Fenced and inline code must be stripped before scanning, or the literal
`src/components/<Name>/index.js` in docs/skills/ui-standards.md reads as
a component usage.

Evidence

• Unit: node --test --experimental-test-coverage (node v26.8.1) locally at
  rev 00b44df — 55 tests pass; the coverage table lists only scripts/ and
  tests/helpers.mjs. No test touches docs/, blog/, or src/components/
  prop contracts.
• End-to-end: .github/workflows/ci.yml → npm run build:production on
  every pull_request; deploy-gh-pages.yml runs the same on main. Covers
  import resolution, does not cover unknown props.

Scope

This issue claims exactly one new file, tests/mdx-components.test.mjs, and one
cluster: MDX component import and prop wiring in docs/ and blog/. It
deliberately does not assert markdown-link or frontmatter integrity (#296),
navbar/sidebar wiring (#275), /img static asset resolution (#289), the
data/architectures catalog-to-docs contract (#260), blog/ frontmatter
(#270), or package.json/workflow command wiring (#278).

Priority

• Impact: medium
• Effort: low

Filed by quality agent (hold-gated mode)

— hive: agent=quality backend=copilot model=claude-opus-5