The contract said the state file was written after every scan, but the script
had no state-file logic at all. This PR adds:
1. Host filesystem scanning (probe_host_filesystems) - probes df on all PVE nodes
2. State file I/O (read_state_file/write_state_file) - absolute path from script location
3. Band classification (classify_band) - HOST-WARN/AMBER/RED thresholds
4. Transition detection (detect_transitions) - alerts on escalation/recovery
5. CLI flags (--hosts-only, --guests-only) to control which parts run
The contract now specifies the state file path resolves from the script's own
location (not CWD-relative), so two different execution contexts cannot write
to two different places.
root
8ed3b9c606