Apply the guidance from the Mandu docs page at https://mandujs.com/docs/migrate/index to my project.

Summary of the page:
Migrate hub. Porting guides from Next.js, Vite, Remix.

Then:
1. Make the change in my codebase consistent with the page.
2. Run `bun run guard` and `bun run check` to verify nothing
   in src/ or app/ breaks Mandu's invariants.
3. Show me the diff and any guard violations.