executor/Sergeant Hartman: add support for boot loop counts < 1
Currently, Sergeant Hartman does not behave well if we set boot loop counts smaller than 1. Let's fix that, and tweak the behaviour to better-map to what the user may actually intend.
- 0: Perform registration, but no bootloops. Quick check still active.
- -1: Do not perform registration or bootloops. No quick checks.