v0.133.0: a restore-test can never fill a box's disk; leftovers retried on a timer (R-672, R-673)

Space preflight before anything is created (uncompressed size from the vzdump log / PBS
snapshot, x1.2 + 5 GiB, thin metadata, off the tested guest's pool when another storage
is eligible, unknown refuses, reported as a non-pass result). Failed scratch teardown and
the stale-lock sweep retried every 10 min (the sweep under the heavy-op gate). A thin
pool crossing 90% requests an immediate host report. Six red-proofs.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

internal/storage/observe.go

@@ -6,6 +6,7 @@ import (
 	"log/slog"
 	"regexp"
 	"strings"
+	"sync"
 
 	"gitea.dooplex.hu/admin/felhom-agent/internal/hub"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/proxmox"
@@ -35,6 +36,45 @@ type Observer struct {
 	host   HostReader
 	ops    HostOps
 	logger *slog.Logger
+
+	// R-672 (v0.133.0): a thin pool crossing thinPoolAlarmFraction (data OR metadata) requests an
+	// out-of-band host report at once, so the hub's storage-fill alarm sees it in seconds instead of at
+	// the next 15-minute report. Rising edge per pool; re-armed below thinPoolRearmFraction.
+	highMu     sync.Mutex
+	high       map[string]bool
+	onThinHigh func()
+}
+
+const (
+	thinPoolAlarmFraction = 0.90
+	thinPoolRearmFraction = 0.85
+)
+
+// SetThinHighTrigger wires the out-of-band report request (main: the storage trigger channel).
+func (o *Observer) SetThinHighTrigger(f func()) { o.onThinHigh = f }
+
+// noteThinFill is the edge detector. key separates data from metadata so each has its own edge.
+func (o *Observer) noteThinFill(key string, frac float64) {
+	o.highMu.Lock()
+	if o.high == nil {
+		o.high = map[string]bool{}
+	}
+	fire := false
+	switch {
+	case frac >= thinPoolAlarmFraction && !o.high[key]:
+		o.high[key] = true
+		fire = true
+	case frac < thinPoolRearmFraction && o.high[key]:
+		o.high[key] = false
+	}
+	o.highMu.Unlock()
+	if fire {
+		o.logger.Error("storage: thin pool crossed 90% — requesting an immediate host report (the hub alarms)",
+			"pool", key, "fraction", frac)
+		if o.onThinHigh != nil {
+			o.onThinHigh()
+		}
+	}
 }
 
 // NewObserver builds an Observer. host defaults to a ProcHostReader; logger to the
@@ -260,6 +300,7 @@ func (o *Observer) build(s proxmox.Storage, mounts []Mount) observed {
 			o.logger.Warn("storage: lvmthin pool data fill is high (a full pool corrupts every guest on it)",
 				"storage", s.Storage, "data_used_fraction", frac)
 		}
+		o.noteThinFill(s.Storage+"/data", frac)
 	}
 
 	// SMART-only device hint (v0.95.0): a dir-storage that lives INSIDE a shared filesystem (the