feat(seo): expand structured data with shared jsonld helpers (#126)

[Escelit]

Summary

Generalizes the ad-hoc Article JSON-LD in CaseStudies.tsx into a typed src/utils/jsonld.ts helper module and closes the structured-data coverage gaps across the site.

Changes

• New src/utils/jsonld.ts: typed helpers organization(), article(), faqPage(), howTo(), breadcrumbList() (plus exported SITE_URL).
• CaseStudies.tsx: refactored to consume article() + now emits a BreadcrumbList on /case-studies/:slug.
• Blog.tsx: emits an Article per blog post (from MDX frontmatter) + BreadcrumbList on both the list and /blog/:slug.
• Faq.tsx: emits a FAQPage built from src/data/faq.json.
• Grants.tsx: emits a HowTo for the grant application steps derived from wave.
• New BlogAuthor.tsx + /blog/author/:id route: emits a BreadcrumbList (closes the third nested-route gap).
• scripts/validate-jsonld.mjs: rebuilds every emitted blob from real data and validates it against a local schema.org structural validator. Wired into CI via pnpm validate:jsonld.

Acceptance

• Every blog post emits a valid Article block
• /faq emits a valid FAQPage block with every Q&A
• Nested routes emit BreadcrumbList (/case-studies/:slug, /blog/:slug, /blog/author/:id)
• Validator script exits 0 in CI
• Build passes (tsc + vite build green)
• Lighthouse SEO unchanged (adds structured data only)

Test plan

• pnpm validate:jsonld → all 8 blobs valid, exits 0
• pnpm build → green
• pnpm format:check → clean

Closes #126

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[truthixify]

Thanks @Escelit. Conflicts on src/pages/Blog.tsx against #136.

This is the last of the three in the order I suggested on #138, since the BreadcrumbList here covers the /blog/author/:id route that #138 adds. Worth rebasing after those two land so you only do it once.

[Escelit]

Successfully rebased

[Escelit]

succesfully rebased

[truthixify]

Heads up: this went conflicted a few minutes ago because #146 and the other blog work, so this is the last of your three as planned landed on develop. It was mergeable right before that, so nothing is wrong with your work.

git fetch origin
git rebase origin/develop

and it should be good to go.

[truthixify]

Conflicted as expected now that #137 has landed. This is the last of your three, so one more rebase and it should be done.

git fetch origin
git rebase origin/develop

[Escelit]

Rebase successfully done. Please review