Breaking: A2A endpoints moved to convention-based URLs for protocol alignment

A2A protocol endpoints have been updated to follow standardized URL conventions, and related payloads were aligned to the protocol. Clients must migrate to the new paths to remain compatible with future releases.

Details

Update client base paths and payload shapes to the new conventions
Use the new Agent Card retrieval endpoint where applicable
Plan a staged rollout to minimize downtime and validate behavior

Who this is for: Integration teams and platform owners maintaining A2A clients and cross-system agent orchestration.