api daemon protocol

Daemon protocol (packages/agent/src/protocol.ts)

Wire protocol versions: DAEMON_PROTOCOL_VERSION (incompatible changes bump this) and DAEMON_SCHEMA_REVISION. Classification rules: backward-compatible / capability-gated / incompatible. Capabilities (packages/agent/src/protocol.ts) must be negotiated; clients check before sending new commands or depending on events. New daemon commands must not be part of startup without a protocol/capability gate. Every wire change updates compatibility maps and both new-client/old-daemon and old-client/new-daemon tests.

Related: Agent package