[FEATURE] A2A migration from v0 to v1 #1941

📋 Prerequisites

• I have searched the existing issues to avoid creating a duplicate
• By submitting this issue, you agree to follow our Code of Conduct

📝 Feature Summary

A2A migration from v0 to v1

❓ Problem Statement / Motivation

Get rid of old deprecated A2A version (v0.3) and unofficial trpc-a2a-go library in go/core (see #1336) and replace everything with official A2A v1 SDKs in python, js, and go.

💡 Proposed Solution

a2a-migration-plan.md

🔄 Alternatives Considered

See above docs

🎯 Affected Service(s)

Controller, CLI, UI, Python and Go agent runtimes, Python BYO SDKs, CRDs, potentially helm charts

📚 Additional Context

3 PRs for each release documented above

#1921
#1929
#1936

🙋 Are you willing to contribute?

• I am willing to submit a PR for this feature