feat: the catalog becomes a documentation site, on Astro

[YaelAnaya]

Stacked on #6. Review that one first; this PR's diff is only the docs site.

examples/catalog was one long page of specimens for manual inspection. It becomes a documentation site: a page per component with a lede, the library its behaviour comes from, live demos, the usage a consumer copies, an anatomy tree and an API table. Plus Introduction, Installation, Theming and States.

Astro 7 with React islands and Tailwind v4, in the same folder, still a workspace member importing the real package through the real exports map.

Component pages	40
Section pages	4
Live demos with source panels	142
Generated API parts	234

It dogfoods the package

The left navigation is the package's own Sidebar, search is a CommandDialog over a build-time index, the API tables are its Table, and the callout, the buttons and the keyboard hints are its Badge, Button and Kbd. Where a page needs no interaction the React component renders to static HTML with no client JS.

Demos are the code sample

One story per file under src/demos/<name>/, and Preview.astro reads that file's own source for the "View Code" panel. A sample cannot drift from what it renders, and forty pages could be authored in parallel without touching a shared file.

API tables are generated

scripts/extract-api.ts reads src/components/*.tsx with the TypeScript compiler API: cva variants with their defaults, declared props with their JSDoc, and inherited props a component gives a default to. The JSON lands in a gitignored folder. tests/docs/api-extractor.test.ts holds the shape against every declaration style the components actually use, and fails the day a component has no page.

Scripts

pnpm catalog and pnpm catalog:check become pnpm docs:dev and pnpm docs:check. The colon is not decoration: pnpm docs is a pnpm built-in and shadows a script of that name.

docs:dev stops a running dev server and drops Vite's dependency cache before it builds. A package rebuilt under a live dev server can leave the optimizer serving two incompatible bundles, and then every island fails to hydrate while the server-rendered HTML still looks correct. Measured cost of always starting clean: none, cold and warm startup are both eight seconds.

Verification

pnpm verify passes: format, lint, 126 tests in 16 files, the build, astro check with zero errors, 46 pages built, and the packed-consumer test. Checked in the browser in both themes: the theme toggle, the search palette, the code panels, and the Dialog, Drawer, ContextMenu, Combobox and Sidebar demos.

Not included, deliberately: a deploy workflow, a "Copy Page" button, full-text search, and ESLint for .astro files.