chore: merge upstream fumadocs (cee687f2e)

- Merged latest changes from fuma-nama/fumadocs upstream
- Rebranded all documentation content from Fumadocs to Hanzo Docs
- Updated package references to @hanzo/docs-* namespace
- Renamed what-is-fumadocs.mdx to what-is-hanzo-docs.mdx
- Kept Hanzo package versions and changelogs

Upstream changes include:
- Python: fix bundle size
- Core: Support <auto-files /> syntax
- OpenAPI: Fix Parameter Serialization
- Obsidian: fix slugification
- UI: improve details
- Docs: introduce type-safe slugs option

examples/python/app/docs/layout.tsx

@@ -5,7 +5,7 @@ import { source } from '@/lib/source';
 
 export default function Layout({ children }: { children: ReactNode }) {
   return (
-    <DocsLayout tree={source.pageTree} {...baseOptions()}>
+    <DocsLayout tree={source.getPageTree()} {...baseOptions()}>
       {children}
     </DocsLayout>
   );