Method touch

src/server/session_manager.py:130–138

Bump ``last_active_at`` (e.g., on each message exchange). Use from server hot paths to keep the idle reaper accurate.

(self, session_id: str)

        update_last_active(session_id, now, path=self.index_path)

    def touch(self, session_id: str) -> None:
        """Bump ``last_active_at`` (e.g., on each message exchange).

        Use from server hot paths to keep the idle reaper accurate.
        """
        info = self._sessions.get(session_id)
        if info is None:
            return
        info.last_active_at = time.time()

    async def stop_session(self, session_id: str) -> None:
        """Transition through STOPPING → STOPPED, killing the subprocess."""