anti
51ecd0924e
Resolves the E.4 hold from Phase E. F.0's Command.followed_by_prompt
gives us the exit-code proxy (prompt-after-last-command) we couldn't
get in Phase E.
Logic: last command without trailing prompt → abrupt; first_token_hash
in {exit, logout, quit, logoff} → graceful; any of the last K=3
commands' first_token_hash in {history, unset, rm, shred, clear, kill}
→ cleanup; else → graceful (clean Ctrl-D / window close).