Compacts the current session (summarize) to advance the context boundary,
then prompts the focused task into the same session with promptAsync. The
session ID never changes and older messages stay visible in the transcript.
Registers a session_restart tool that spawns a fresh child session on
the current project, prompts it with a focused task (+ optional notes)
via promptAsync, and aborts the current session by default so a single
focused task continues in a clean context window instead of compacting.
Includes an experimental.compaction.autocontinue hook to reject the
synthetic continue turn after compaction (default on).
