Rename every XRPC, wire field, Rust type, function, env var and test that said agent when it meant an account this server hosts. `bot.did.provisionAgent` is now `bot.did.createAccount`, the other ten account XRPCs follow the same pattern, `agentId`/`agentToken`/`agents` become `accountId`/`accountToken`/`accounts` on the wire, `DIDBOT_AGENT_TOKEN{,_FILE}` become `DIDBOT_ACCOUNT_TOKEN{,_FILE}`, and the log's two token entries move with them, so a data directory from the build before this one is refused. `kind: agent` stays: it is a label the server never interprets. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Change-Id: Ida9bcd519a05e08ee0c926cb217ecf8288a5f18a