Two bugs surfaced running the 0.5.0 drill with --purge-storage on a
cold btrfs pool:
1. wait_agent dumped the VM's RAW console log on timeout — full of
terminal escape sequences and a firmware menu — which scrambled the
operator's terminal, and doubly so when it landed in a log they were
tail -f'ing ('*Debian GNU/Linux', 'ESC to return previous menu',
^[^[^[). Now: capture to /tmp/box-console-<n>.log, strip everything
but printable ASCII + tab/newline, print only a short sanitized tail.
Nothing raw reaches a terminal.
2. A failed mint left its stuck VM running, starving the NEXT box's boot
and cascading more 5-min timeouts (tpl failed → codex failed). Every
mint-failure branch now tears the box down before continuing.
c4cc9f43d1