B1: fly-loop-reset runs only /opt/fly/sbin/flysim, a root-owned copy
05-deploy installs from the release tarball after checking it against
the tarball's MANIFEST; fixed paths, fly.env parsed as data, env -i.
B2: the wrapper pauses fly-watchdog.timer (and waits out a running
probe) for the reset, and starts flysim and the timer on every exit.
H1: a step that raises or times out is a failed step; the ladder state
is saved before the step runs. H2: one --list call computes the build's
compatibility once; TimeoutStartSec 25 min. H3: level 2+ resets to the
rung below the best or restarts, never lower.
Tests run the wrapper against a fake flysim, systemctl and archives.