a2a-web-client v0.4.0

Added

• (a2a-agents) MCP server over Streamable HTTP transport

Documentation

• Doc-comment audit, add ROADMAP, retire stale planning docs

Feat

• (a2a-rs) Client Transport port + JSON-RPC 2.0 client + card negotiation

Refactor

• (a2a-rs) Split streaming & push out of storage adapters (Phase 4 final)