Docs: knit explainer pages into one "How MateMate Works" site (closes #174)

[testtest126]

Ties the public GitHub Pages explainers into one small "How MateMate Works" site, borrowing the information architecture of Google's How Search Works — plain-language question-based entry points, overview → deep-dive progressive disclosure, consistent modular cards, and a light shared top-nav across pages.

Reconciled with #160

While this was in progress, #160 merged the fleet page docs/the-fleet/index.html ("How the Agents Talked"). Rather than duplicate/overwrite it, this PR adopts #160's page as canonical and knits around it. My hand-authored fleet page was dropped; #160's content is unchanged.

What's here (rebased on main @ 0f5e8f7)

• docs/index.html (new, +200) — the "How MateMate Works" hub / front door. Two question-based entry cards: What is MateMate? → architecture, How was it built? → the fleet; plus an at-a-glance strip and provenance footer.
• docs/architecture/index.html (nav-only, 24/-11) — its nav becomes the shared cross-page top-nav (brand → hub; Overview / What is it? / How it was built?), keeping its own section anchors.
• docs/the-fleet/index.html (docs: publish 'How the Agents Talked' (the making-of, public/softened… #160's page, +36, no content change) — adds the same shared top-nav, themed with that page's own design tokens so it adapts across its light/dark and lineage skins (Codex / Chaturanga / Persia / al-Andalus / Terminal). The fixed skin dial relocates to bottom-right on mobile so it clears the nav.

Constraints honored

• Each page stays a single self-contained HTML file — no external fonts, scripts, or assets (verified none added).
• Theme-aware and reduced-motion aware; the fleet nav respects docs: publish 'How the Agents Talked' (the making-of, public/softened… #160's skin system.
• PII-clean — scanned for emails, names, bundle ids, private paths, deploy slugs, secrets: none.

Verified locally (in-browser preview over a static docs/ server)

• All three pages render; every cross-page link resolves (hub ⇄ architecture ⇄ the-fleet); "current page" pill marked on each.
• Fleet nav adapts across skins (confirmed Terminal → phosphor-green) and its mobile media query relocates the skin dial (confirmed via CSSOM); no dial/pill overlap on desktop.
• Hub + architecture verified dark and mobile earlier. No console errors.

Docs-only diff — no Swift/iOS/server surface, so ChessKit/Server/iOS builds are unaffected; required CI checks should pass trivially on the current merge state.

Security-sensitive: no · App-touching: no (docs only) · Shared files: none

Closes #174

[testtest126]

Merge request → orchestrator

• PR Docs: knit explainer pages into one "How MateMate Works" site (closes #174) #176 @ 9c094f013cdedb93aa0afe3ceb6887e26999d1bc — Closes Docs: knit the public explainer pages into one "How MateMate Works" site (hub + shared nav + fleet page) #174
• Verified locally: in-browser preview over a static docs/ server — all three pages render dark + light + mobile; every cross-page link resolves (hub ⇄ architecture ⇄ the-fleet); the fleet "Life of a PR" stepper behaves (clean → all-green on main; blocked → stale check fails, gate red, orchestrator-approval never posted); no console errors; PII scan clean; no external assets.
• Build legs: docs-only diff (no Swift/iOS/server surface) — ChessKit/Server/iOS builds unaffected; required CI checks should pass trivially on the current merge state.
• Security-sensitive: no
• App-touching: no (docs only — no iOS-lane gate needed)
• Shared files: none

Any new push voids this — re-request would follow with the new head SHA.

[testtest126]

⚠️ Retract the merge request above — collision detected, do not merge.

Fresher git evidence supersedes my prior merge request: main advanced to 0f5e8f7, and commit 1eb80ff (merged via #160) already publishes docs/the-fleet/index.html — "How the Agents Talked". This PR also creates that file, hence the CONFLICTING state. I will not overwrite #160's merged, reviewed fleet page.

Only my fleet page collides. The other two parts of this PR are additive and conflict-free:

• docs/index.html — the "How MateMate Works" hub (main has no root index).
• docs/architecture/index.html — shared cross-page nav retrofit (nav-only).

Marking this draft while I reconcile. Planned resolution (pending direction): rebase onto 0f5e8f7, keep #160's fleet page, drop my duplicate, keep the hub + architecture nav, and extend the shared top-nav onto #160's fleet page so all three pages are knit into one site. No merge until this is clean and re-requested at a new head.

[testtest126]

Merge request → orchestrator (fresh, supersedes the retraction above)

Reconciled and rebased onto current main (0f5e8f7); the earlier conflict is gone.

• PR Docs: knit explainer pages into one "How MateMate Works" site (closes #174) #176 @ 7231c123c8057b040c96a47a702de7881a76f5c8 — Closes Docs: knit the public explainer pages into one "How MateMate Works" site (hub + shared nav + fleet page) #174 — mergeable: MERGEABLE
• Scope: additive — new docs/index.html hub + shared top-nav on docs/architecture/index.html (nav-only) and on docs: publish 'How the Agents Talked' (the making-of, public/softened… #160's docs/the-fleet/index.html (+36, no content change, nav themed in that page's own tokens/skins).
• Adopts docs: publish 'How the Agents Talked' (the making-of, public/softened… #160's fleet page as canonical — did not overwrite it.
• Verified locally: all three pages render; cross-page links resolve; fleet nav adapts across docs: publish 'How the Agents Talked' (the making-of, public/softened… #160's skins (Terminal → green) and relocates its skin dial on mobile (CSSOM-confirmed); no console errors; PII-clean; no external assets added.
• Build legs: docs-only — ChessKit/Server/iOS unaffected; required checks should pass trivially on the current merge state.
• Security-sensitive: no · App-touching: no (no iOS-lane gate) · Shared files: none

Any new push voids this; I'll re-request at the new head.