Adds a user-configurable "Failed Services" alert that notifies when any
tracked systemd service enters the failed state, and again when all services
recover.
---------
Signed-off-by: Martin Stenröse <martin@stenrose.se>
Co-authored-by: henrygd <hank@henrygd.me>
- track pool capacity, health, I/O, scrub status, and vdev errors
- report dataset usage and correct ZFS filesystem metrics
- add pool charts, detail views, refresh controls, and health alerts
- persist pool details and include ZFS usage in disk alerts
- support configurable detail intervals and legacy agent compatibility
---------
Co-authored-by: hank <hank@henrygd.me>
- Report battery data for individual devices
- Select a representative battery for legacy fields and alerts
- Average named battery data independently
- Display multiple batteries in system charts
- Add cross-platform coverage and transport tests
- Introduced a new test file `alerts_disk_test.go` to validate the behavior of disk alerts using historical data for extra filesystems.
- Enhanced the `HandleSystemAlerts` function to correctly calculate disk usage for extra filesystems based on historical records.
- Updated the `SystemAlertStats` struct to include `ExtraFs` for tracking additional filesystem statistics.
Use Info.BandwidthBytes converted to MB/s with float division so
bandwidth alert checks are based on current data without integer
truncation near thresholds.