Contracts the eight transcript row kinds, daemon-vs-client decisions, the
transcript/reduced-state projections and their cursor/replay semantics, the
ACP handshake and declined capabilities, the adapter install command, and
the approval nonce rules (generation, live-only placement, secrecy from the
agent and durable history, single-use/duplicate resolution) and bounded
prompt/cancel liveness.
Amends RESTART.md to state plainly that a structured session's agent is a
daemon child, not tmux-backed: a restart ends the active turn, the
transcript survives in the event log, and pending approvals/nonces do not.
Refs #137
