[Task]: 1.0: Support multi-tenancy #672
Description
a2aproject/A2A#1195 updates core proto with extra HTTP bindings prefixed with /{tenant}. It should be supported.
It's not fully clear how to represent it for JSON-RPC, also HTTP+JSON/REST protocol binding in the spec doesn't mention it, see a2aproject/A2A#1273 and https://a2a-protocol.org/latest/specification/#53-method-mapping-reference.