WebClient tutorials: Convert tutorials to use Vite instead of NextJS

I think we should switch to using Vite instead of NextJS. Vite allows us not to worry about server-side rendering and the issues that come with that when using the web client SDK. This will allow for cleaner and more readable tutorial code.

Nevertheless, I think we should include a separate section (disclaimer) in the docs that, when using NextJS, one has to use dynamic imports (including an example), which should be clearly visible to anyone working with the web SDK.

One of our pioneers, Zoro, are using Vite for their frontend, and I must say that their web client code is by far more cleaner than our current tutorial code, since they can avoid the dynamic import restriction using Vite.

Find the existing Next.js tutorial code in the repository, likely in a `web-client` or similar directory. Understand how the current examples work and the dynamic import pattern mentioned. Research Vite setup and create equivalent examples. The goal is to replace the tutorial code with Vite-based versions and add a clear Next.js disclaimer section to the documentation.

索引モデルが issue の本文から書いたものです。