* fix(lifecycle): reject session work once close has started Process shutdown closed the shared binary session without sealing it, so a stdio tool call could open a provider after that close and leave the child running. GDB ran a queued console command or a second close after the session had started closing because the queued turn did not repeat admission checks. Shutdown now refuses later target acquisition, and a queued GDB command or duplicate close fails as unavailable once its turn finds the session closing or gone. Co-authored-by: morluto <morluto@users.noreply.github.com> * fix(gdb): block console admission after cleanup starts --------- Co-authored-by: Cursor Agent <cursoragent@cursor.com> Co-authored-by: morluto <morluto@users.noreply.github.com>