docs(site): Fumadocs documentation site on TanStack Start

New standalone app at docs-site/ — Fumadocs (fumadocs-core/ui 16, fumadocs-mdx
15) on TanStack Start (Vite 7 + nitro-v2 bun preset, React 19, Tailwind 4),
mirroring the web/ console stack but with no auth/i18n/orval — docs stay public.

- catch-all docs route (routes/docs/$.tsx), Orama search (routes/api/search.ts),
  RootProvider shell, MDX component map, shared nav, custom 404
- content/docs/: hand-written index.mdx + meta.json nav, plus 7 pages imported
  from repo docs/ + README (leading H1 stripped, YAML frontmatter added; kept as
  .md so existing </{ don't trip MDX JSX). Content is a one-time snapshot.
- mdx() is plugins[0]; tsconfig collections/* -> ./.source/*; SSR search variant;
  @source for fumadocs-ui classes. Generated .source/routeTree/dist/.output ignored.

Verified: bun run build (client+SSR+nitro) green, tsc clean, dev + prod servers
serve all routes 200 with SSR content + nav, search returns hits, 404 works.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs-site/vite.config.ts

@@ -0,0 +1,30 @@
+import { defineConfig } from 'vite'
+import tsConfigPaths from 'vite-tsconfig-paths'
+import tailwindcss from '@tailwindcss/vite'
+import mdx from 'fumadocs-mdx/vite'
+import { tanstackStart } from '@tanstack/react-start/plugin/vite'
+import { nitroV2Plugin } from '@tanstack/nitro-v2-vite-plugin'
+import viteReact from '@vitejs/plugin-react'
+
+export default defineConfig({
+  server: { port: 3001 },
+  plugins: [
+    // Fumadocs MDX must run first: it registers the resolver/loader that transforms
+    // .md/.mdx and emits the `.source` typegen (the `collections/*` virtual modules the
+    // docs route imports), before route generation and the React transform.
+    mdx(),
+    tsConfigPaths({ projects: ['./tsconfig.json'] }),
+    tailwindcss(),
+    // Full SSR on the TanStack Start runtime; the docs render server-side then hydrate.
+    tanstackStart(),
+    // Nitro v2 is the deployment target: the `bun` preset bundles a Bun-runnable server
+    // to .output/ (`bun run .output/server/index.mjs`), matching the rest of the project.
+    nitroV2Plugin({
+      preset: 'bun',
+      compatibilityDate: '2026-06-12',
+    }),
+    // Must come AFTER tanstackStart — provides the React JSX transform + Refresh runtime
+    // that Start's dev mode requires.
+    viteReact(),
+  ],
+})