Create official Next.js and Vite sample projects for ADK-TS

[Softdev1]

Description

Build and document official sample projects demonstrating how to use ADK-TS in Next.js and Vite setups. Include examples of SSR with streaming, hydration-safe patterns, and best practices for production-ready integrations.

[Timonwa]

@Softdev1 , @Adebesin-Cell , this is supposed to be in the adk-ts samples repo

But we can also still have a simpler version for the Vite starter template, just as we have Next.js starter template