Add live per-disk usage, disk read/write and network in/out rates to the
instance Overview tab, the instances list and the dashboard top-loaded list.
Backend:
- get_vm_fsinfo() pulls per-filesystem usage via QEMU guest agent
- metrics_broadcaster computes I/O rates (bytes/sec) from cumulative counters
- instances-list loop now refreshes each running VM via status/current
(1s-granular) instead of cluster/resources (10s pvestatd), with bounded
concurrency, and paces both realtime loops to a 1s cadence
Frontend:
- OverviewTab: per-disk cards, Network I/O and I/O-rate cards via WS
- InstancesPage: Net and Disk I/O columns; Disk% shown for LXC only
- DashboardPage: top-loaded list overlaid with realtime metrics
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
