fix(cli): make Ctrl-C escape shell loops and abort cleanly

An interactive shell only aborts a while true; do entire ...; done loop when the child is killed by SIGINT (WIFSIGNALED). entire trapped SIGINT and exited normally, so every Ctrl-C just ended one iteration and the loop instantly respawned entire — the user could never break out.

• On abort, re-raise SIGINT to self (dieFromInterrupt) so the process dies by the signal and enclosing loops break on a single Ctrl-C.
• Second Ctrl-C force-quits, so a genuinely stuck shutdown still has an escape hatch (the first signal now only cancels + warns).
• Treat context.Canceled as a silent 130 exit instead of dumping the raw transport/keyring cancellation string as if it were a failure.