Magic Link / OTP sign-in was requested here early on and still isn't in the registry. I've built it: `magic-link-auth` blocks for Next.js and React first, mirroring the structure of the password-based-auth blocks, the signInWithOtp flow, the check-your-email screen, the token verification route, and the docs pages for both frameworks. Opening the PR now, happy to follow up with the other frameworks if useful.