A2UI migration

This skill is a router. It identifies what is being migrated and then sends you to the guide for that case. A case is identified by three facts:

1. Language / platform: Dart (Flutter), TypeScript (Lit, Angular, React, web core), Python (agent SDKs, ADK, A2A), Swift, Kotlin.
2. Source: the SDK or package the code uses today and its version, and the protocol version it speaks on the wire.
3. Target: the SDK the code should use afterwards, and the protocol version it should speak.

Do not start editing before all three are written down. A migration that changes the SDK and the wire version at the same time is two migrations; split it when the agent and the renderer are not released together.

Step 1: identify the language and the source SDK

Read the manifests in the repository, not just the file extensions: