## Summary
- `contentlayer2@0.4.6` is unmaintained and drags in a heavy, stale
dependency graph (esbuild pinned to 0.17–0.20, mdx-bundler, old
`@opentelemetry/core`) that was the recurring source of vuln bumps.
- Migrates all three apps that used it — `design-system`, `ui-library`,
`learn` — to [Velite](https://velite.js.org), preserving the generated
typed `allDocs`/`Doc` collection and the `body.code` + `useMDXComponent`
runtime via a small shared local hook.
- Same MDX pipeline (remark-gfm, remark-code-import, rehype-slug,
rehype-pretty-code w/ Shiki compat + local theme,
rehype-autolink-headings, custom
`__rawString__`/`__src__`/`__event__`/`__style__` visitors) ported 1:1
into each app's `velite.config.js`.
- `learn`'s extra frontmatter fields (`chapterNumber`, `explore`,
`courseHero`) are now backed by real Velite/Zod schema types, so the
`(doc as any)` casts in `get-next-page.ts` / `get-current-chapter.ts` /
the doc page could be dropped.
- `next.config.mjs` no longer wraps with `withContentlayer`; since
Velite has no Next.js webpack-plugin equivalent, each app's `dev` script
now runs `velite dev` and `next dev` in parallel via `npm-run-all`.
Ref:
[FE-3861](https://linear.app/supabase/issue/FE-3861/migrate-off-contentlayer2-learn-ui-library-design-system-to-shed)
## Test plan
- [x] `pnpm build:content` (Velite build) succeeds for all three apps
- [x] `pnpm typecheck` passes for all three apps
- [ ] Manual smoke test of `pnpm dev` for each app in a browser (docs
pages render, TOC, copy-button, code highlighting)
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Improvements**
* Improved content generation across documentation, learning materials,
and the UI library for more consistent pages.
* Preserved MDX rendering, navigation, table of contents, course
metadata, source previews, and component examples.
* Improved consistency when displaying documentation and interactive
examples.
* Improved application loading by optimizing how interface components
are delivered.
* **Chores**
* Streamlined content compilation and development workflows across the
design system, learning area, and UI library.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
## What kind of change does this PR introduce?
Chore
## What is the current behavior?
Design system still uses the old CustomFont family, so documented
components no longer match Studio, www, and docs after the Inter /
Manrope rollout.
## What is the new behavior?
Design system uses the same font stack as the other apps:
- Inter for body (`--font-sans`)
- Manrope for headings (`--font-heading`)
- Source Code Pro for mono
Also adopts the Inter-optimised type scale and base weight (`450`) used
in Studio.
## Additional context
Based on Francesco's unshipped `chore/update-fonts` draft (design-system
slice only). Related shipped work: #47306, #47227.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Style**
* Updated the design system with refreshed typography using Inter and
Manrope, with Source Code Pro for code.
* Refined theme typography and spacing tokens, including a more complete
text scale, updated font weights, and container sizing.
* Improved heading styling and ensured `code`/`pre`/`kbd`/`samp` use
consistent monospace treatment.
* Adjusted default border styling and improved font loading/fallback
behavior for more consistent rendering.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
## What kind of change does this PR introduce?
Add `Markdown` component
- as a ui-pattern
- docs in design-system
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Introduced a Markdown UI pattern with full documentation and a docs
sidebar entry.
* Markdown component supports composable renderers, optional lazy syntax
highlighting, and customizable element overrides.
* Added many interactive examples (full demo, headings, paragraphs,
lists, links, inline code, blockquotes, code blocks, tables, images,
horizontal rules) plus Quote and Avatar demos.
* **Documentation**
* New MDX guide detailing usage, props, and customization previews.
<!-- review_stack_entry_start -->
[](https://app.coderabbit.ai/change-stack/supabase/supabase/pull/46325?utm_source=github_walkthrough&utm_medium=github&utm_campaign=change_stack)
<!-- review_stack_entry_end -->
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
- Most changes are related to either types or `useRef` usages (it now
requires an initial value).
- also updated `vaul` to its latest version and haven't noticed any
change ([design-system
demo](https://design-system-git-react-19-supabase.vercel.app/design-system/docs/components/drawer))
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Upgraded workspace to React 19.
* **Bug Fixes**
* Improved null-safety and ref handling across editors, UI components,
shortcuts, and markdown/image rendering to reduce runtime errors.
* Safer event/timeout/interval cleanup and more robust command/context
handling.
* **Chores**
* Bumped vaul dependency versions.
* **Documentation**
* Type and TypeScript accuracy improvements for clearer developer
feedback.
<!-- review_stack_entry_start -->
[](https://app.coderabbit.ai/change-stack/supabase/supabase/pull/45886)
<!-- review_stack_entry_end -->
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Sorted all imports in all packages, `cms`, `design-system` and
`ui-library` apps by running `pnpm format` on them.
All changes in this PR are done by the script.
* Remove extra file.
* Remove unneeded tsconfig.jsons.
* Add @/* alias for importing in-package files to all apps.
* Remove baseUrl from all apps except studio (it'll require changes in almost all files).
* Fix baseUrl issues in docs, ui-library and design-system.
* Fix the typecheck for cms app. Fix all baseUrl errors in the cms app.
* Add deprecated flag to baseUrl in www.
* Add all missing libraries in the packages/apps.
* Add all missing Vitest imports to the tests.
* Add some missing exports to ui.
* Fix the admonition export.
* Fix various minor bugs.
* Migrate the ui package to use vitest.
