…nto vlk/split-out-blog-route

…nto vlk/split-out-blog-route

- Use String.startsWith instead of String.includes for blog route
  filtering to avoid accidentally excluding non-blog routes that
  contain 'blog' as a substring

- Replace JsExn.throw with JsError.throwWithMessage in
  BlogArticleRoute for consistency with BlogApi.res and to get
  proper Error objects with stack traces

- Normalize path separators in MdxFile.scanDir to fix Windows
  compatibility where Node.Path.join2 produces backslashes

Updates the Markdown image caption test to use a new caption and image.
Regenerates all related test screenshots to reflect the change.

Add detailed instructions for running and updating Vitest
browser-based unit tests in the README. Remove outdated
screenshot baseline PNGs from __tests__/__screenshots__.

Add guidance in README to be selective when updating screenshots.

- Add DocsManualRoute for /docs/manual pages with sidebar and TOC
- Implement SidebarHelpers for sidebar nav/category generation
- Add MdxFile.loadAllAttributes for loading manual doc frontmatter
- Update routes to support manual docs and exclude from mdxRoutes
- Document commit/PR conventions in AGENTS.md

- Create DocsReactRoute.res/.resi for /docs/react/* pages, following the
  same pattern as DocsManualRoute with React-specific sidebar categories
  (Overview, Main Concepts, Hooks & State Management, Guides) and
  breadcrumbs (Docs > rescript-react)
- Register docsReactRoutes in app/routes.res via MdxFile.scanPaths and
  filter docs/react paths out of the legacy mdxRoutes
- Fix inconsistent comparator in Mdx.sortSection: items with an order
  field now always sort before items without one, and items without order
  preserve their relative position (was _ => -1.0, now handles all four
  cases explicitly)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

…rescript-lang.org into vlk/split-out-docs-react

…escript-lang.org into vlk/split-out-docs-guidelines

- Create CommunityRoute.res with dedicated loader and community sidebar
- Register communityRoutes in routes.res, filter community from mdxRoutes
- Remove communityTableOfContents, community branches from MdxRoute

…kupDetailRoute

- Create SyntaxLookupDetailRoute.res with dedicated loader for /syntax-lookup/* pages
- Register syntaxLookupDetailRoutes in routes.res, filter syntax-lookup from mdxRoutes
- Remove syntax-lookup branch, mdxSources/activeSyntaxItem fields, and components dict from MdxRoute
- Flatten loader body after if/else removal