[Umbrella] SEO improvements

Tracking issue for the SEO improvements scoped during the initial pass. Each child issue is self-contained and can be picked up independently.

Status legend

• ✅ merged
• 🟡 PR up, awaiting review
• 📝 spec'd (issue or PR open)
• ⬜ not started

High leverage

• ✅ #4 — Use clean URLs (no .html extension) via Netlify rewrites — PR #14
• ✅ #5 — Add Netlify _headers for caching and security — PR #14
• 🟡 #6 — Add "What it does / How to use" content blocks to each tool page — PR #15

Medium leverage

• ✅ #1 — Add JSON-LD structured data (WebSite, WebApplication, BreadcrumbList) — PR #20
• 🟡 #3 — Add cross-tool footer links for internal linking — PR #21
• 🟡 #8 — Add FAQ section with FAQPage JSON-LD per tool — PR #22 (stacked on #21)
• 📝 #57 — Polish meta descriptions for SEO — surface the "no installs, no servers, no tracking" USP
• 📝 #58 — Generate a static favicon.png to replace inline SVG data-URI icons (Google Search doesn't support SVG favicons)
• ⬜ #7 — Add web app manifest for installability

Lower leverage / nice-to-have

• ✅ #10 — Pre-generate og-image.png (decoupling) — PR #17. Size optimization not pursued; can reopen if it becomes meaningful.
• ⬜ #11 — Audit semantic HTML landmarks and heading hierarchy
• ⬜ #12 — Add service worker for offline support

Foundation / tooling

• ✅ #16 — Adopt posthtml-include for shared HTML partials — PR #18
• ⬜ #19 — Evaluate migration to Eleventy after #3/#8 land

Already shipped (merged)

• PR #2 — Google site verification, robots.txt, generated sitemap.xml, social card image, baseline SEO meta tags.
• PR #14 — Clean URLs, Netlify _redirects + _headers, sitemap on clean URLs.
• PR #17 — Pre-generated og-image.png; build now copies instead of rasterizing on every run.
• PR #18 — Shared HTML partials via posthtml-include (meta-base, meta-social, head-fonts, head-theme, footer-script).
• PR #20 — JSON-LD structured data + src/tools.json manifest.

In review

PRs to land in this order — each rebases cleanly onto the previous as it merges:

1. PR #15 (#6) — content sections. Independent of the manifest stack; can land any time.
2. PR #21 (#3) — cross-tool footer links, reads tools.json.
3. PR #22 (#8) — FAQ + FAQPage JSON-LD, reads tools.json. Stacked on PR #21.

Up next after review

1. #58 — Generate favicon.png (32×32 PNG from 🛠️ emoji); update meta-base.html; remove per-tool inline SVG icon tags.
2. #57 — Polish meta descriptions (<meta name="description">, og:description, twitter:description) across all 16 pages to surface the "no installs, no servers, no tracking" USP. Meta tags only — no UI changes.
3. #19 — re-read after #3/#8 land; decide whether to migrate to Eleventy.
4. #7 — PWA manifest. Reuses the same generator pattern as og-image.png (#17) for the icon set.
5. #12 — service worker. Pairs with #7 for the installable PWA experience.
6. #11 — semantic HTML audit. Best done after the content sections (#6) and FAQs (#8) are in place.

Out of scope (intentionally)

• Self-hosting Google Fonts — discussed and deferred.
• Lighthouse CI gating — discussed and deferred.
• Manual Search Console / Bing Webmaster Tools submission — operator task (see closed #9).

This is an umbrella tracker rather than a self-contained change; start by choosing an open child issue such as #57, #58, #7, #11, or #12. Read the referenced entry points, including meta-base.html and src/tools.json, plus the related merged PRs. Done means completing one child issue's stated scope and updating its status, not changing the umbrella issue itself.