agent: embedded MCP server (rmcp) with send/recv tools

CLAUDE.md

@@ -156,6 +156,20 @@ docs/damocles-migration.md   options for moving damocles onto hyperhive
   marks them `failed` with note `"agent state dir missing"` so they fall out
   of `pending`. They stay in sqlite for audit.
 
+## Agent MCP surface
+
+The harness ships an embedded MCP server (rmcp 1.7) that claude can launch
+via `--mcp-config`. Subcommand: `hive-ag3nt mcp`. Tools:
+- `send(to, body)` — message a peer or the operator.
+- `recv()` — drain one inbox message.
+
+Both translate to `AgentRequest::Send`/`Recv` against the agent's own
+`/run/hive/mcp.sock` (the existing hyperhive socket). The MCP surface is
+just claude's view of that socket — same authority, friendlier protocol.
+
+Manager will get its own subcommand later with `request_spawn`, `kill`,
+`request_apply_commit` added to the TOOLS list.
+
 ## Manager (hm1nd) is hive-c0re-managed
 
 The manager container runs through the **same lifecycle as sub-agents** —