Single platform-adapter plugin under plugins/platforms/a2a/ — zero core
edits — that supersedes the entire A2A PR/issue cluster. Built on the
ctx.register_platform + ctx.register_tool surface the codebase now exposes.
Outbound (a2a toolset): a2a_discover / a2a_call / a2a_list let the agent
call any A2A-compliant peer over JSON-RPC message/send. Inbound (platform
adapter): a stdlib http.server serves an Agent Card at
/.well-known/agent.json and routes incoming tasks into the agent's LIVE
gateway session (the #11025 insight) — same agent, full memory — returning
the reply over A2A.
Security on by default: no bearer token => 127.0.0.1-only bind; constant-
time bearer auth; inbound prompt-injection filtering + untrusted-peer
framing; outbound credential redaction; append-only audit log; per-context
conversation persistence outside the compaction pipeline.
Stdlib only (no a2a-sdk). 37 tests incl. a live HTTP round-trip
(card + message/send + reply) and a bearer-auth 401 path.
