Docs-site uplift 🎯

6 build-verified improvements to the OrchestKit Fumadocs site. tsc 0 errors · next build ✓ 269/269 pages.

What changed

#fixbeforeafter
1Prev/next page navmissing site-wide (footer override dropped it)restored via findNeighbour
2Breadcrumbsnoneenabled
3Sidebar IA12 flat top-level sections6-group spine, 0 file moves
4fumadocs-mdx14.3.015.0.10 (+ core/ui 16.9.3, react 19.2)
5"Last updated" dateblank (Vercel shallow clone)build unshallows git first
6JS polyfills~41KB legacy bundle.browserslistrc → dropped

The IA regroup (12 → 6)

Not in this PR (your calls)