hub v0.25.0: per-storage worst-fill alerting (StorageFillChecker)

Generalizes host_disk to any reported storage target (dump/backup volume, data drive,
thin pool, PBS). Per-(host,target) state, born/persistent, natural critical severity,
distinct storage_fill_* events; excludes the root-backed builtin (host_disk owns root).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HxLA1mZurFq9kt8hneFeCs

hub/cmd/hub/main.go

@@ -51,6 +51,10 @@ type Config struct {
 		// (normalizeDiskThresholds). Seed-only config, like stale_threshold.
 		HostDiskWarnPercent float64 `yaml:"host_disk_warn_percent"`
 		HostDiskCritPercent float64 `yaml:"host_disk_crit_percent"`
+		// Per-storage-target fill thresholds (percent). Empty/0/invalid → defaults 90/95. Independent of
+		// the host-root thresholds above so a single storage's policy can be tuned separately.
+		StorageFillWarnPercent float64 `yaml:"storage_fill_warn_percent"`
+		StorageFillCritPercent float64 `yaml:"storage_fill_crit_percent"`
 	} `yaml:"alerting"`
 	Registry struct {
 		Image            string `yaml:"image"`
@@ -330,6 +334,10 @@ func main() {
 	// root disk_percent the agent reports; born/persistent (a disk already full at hub restart alerts on
 	// cycle 1). Distinct event types from the controller's GUEST disk_warning/disk_critical. Same 60s sweep.
 	hostDiskChecker := monitor.NewHostDiskChecker(dataStore, cfg.Alerting.HostDiskWarnPercent, cfg.Alerting.HostDiskCritPercent, dispatcher.ProcessEvent, logger)
+	// v0.25.0: PER-STORAGE worst-fill alert — generalizes the host-root check to any reported storage
+	// target (dump/backup volume, data drive, lvmthin pool, PBS datastore). Born/persistent; excludes the
+	// root-backed builtin (hostDiskChecker owns root, no double-alert); emits natural `critical`. Same sweep.
+	storageFillChecker := monitor.NewStorageFillChecker(dataStore, cfg.Alerting.StorageFillWarnPercent, cfg.Alerting.StorageFillCritPercent, dispatcher.ProcessEvent, logger)
 	go func() {
 		ticker := time.NewTicker(60 * time.Second)
 		defer ticker.Stop()
@@ -343,6 +351,7 @@ func main() {
 				hostCapabilityChecker.Check()
 				hostLeafChecker.Check()
 				hostDiskChecker.Check()
+				storageFillChecker.Check()
 			}
 		}
 	}()