Add a Learn-only sidebar mode that mirrors how /reference works: when a user
is under /learn, the framework picker is hidden and the sidebar shows only
learn content (What's New, Agentic Protocols, Generative UI, Specs,
Architecture, Tutorials).
- Add `learn` to the root meta.json so the learn folder is discoverable in
the page tree (was missing, which is why ConditionalSidebar previously
fell through to the default sidebar on /learn routes)
- Add a static LearnHeader (book icon + "Learn") visually matching the
Reference version selector, wired in via Sidebar's headerSlot
- Rename the learn index page title to "Overview" so the landing page reads
cleanly under the new header
- Drop the redundant `h-6` spacer in Sidebar — every header component
(IntegrationSelector, VersionSelector, LearnHeader) already supplies its
own `mb-3`, and the spacer was producing a 24px phantom gap on /learn
while collapsing to 0 on /reference under flex shrink
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Tyler Slaton