feat(watchdog): hardware error monitor + unified component status store

- Add platform/error_patterns.go: pluggable table of kernel log patterns
  (NVIDIA/GPU, PCIe AER, storage I/O, MCE, EDAC) — extend by adding one struct
- Add app/component_status_db.go: persistent JSON store (component-status.json)
  keyed by "pcie:BDF", "storage:dev", "cpu:all", "memory:all"; OK never
  downgrades Warning or Critical
- Add webui/kmsg_watcher.go: goroutine reads /dev/kmsg during SAT tasks,
  writes Warning to DB for matched hardware errors
- Fix task status: overall_status=FAILED in summary.txt now marks task failed
- Audit routine overlays component DB statuses into bee-audit.json on every read

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/app/sat_overlay.go

@@ -9,7 +9,7 @@ import (
 	"bee/audit/internal/schema"
 )
 
-func applyLatestSATStatuses(snap *schema.HardwareSnapshot, baseDir string) {
+func applyLatestSATStatuses(snap *schema.HardwareSnapshot, baseDir string, db *ComponentStatusDB) {
 	if snap == nil || strings.TrimSpace(baseDir) == "" {
 		return
 	}
@@ -28,6 +28,8 @@ func applyLatestSATStatuses(snap *schema.HardwareSnapshot, baseDir string) {
 	if summary, ok := loadLatestSATSummary(baseDir, "storage-"); ok {
 		applyStorageSAT(snap.Storage, summary)
 	}
+	// Apply unified component status DB — overlaid last so it can only upgrade severity.
+	applyComponentStatusDB(snap, db)
 }
 
 type satSummary struct {
@@ -206,6 +208,86 @@ func matchesGPUVendor(dev schema.HardwarePCIeDevice, vendor string) bool {
 	}
 }
 
+func applyComponentStatusDB(snap *schema.HardwareSnapshot, db *ComponentStatusDB) {
+	if snap == nil || db == nil {
+		return
+	}
+	for _, rec := range db.All() {
+		key := rec.ComponentKey
+		status := dbStatusToSATStatus(rec.Status)
+		if status == "" {
+			continue
+		}
+		detail := rec.ErrorSummary
+		ts := rec.LastChangedAt.UTC().Format("2006-01-02T15:04:05Z")
+
+		switch {
+		case strings.HasPrefix(key, "pcie:"):
+			bdf := strings.TrimPrefix(key, "pcie:")
+			bdf = strings.TrimPrefix(bdf, "gpu:") // strip sub-type if present
+			// bdf may be empty (e.g. "pcie:gpu:nvidia") — skip BDF matching
+			if sanitizeBDFForLookup(bdf) == "" {
+				break
+			}
+			normalized := sanitizeBDFForLookup(bdf)
+			for i := range snap.PCIeDevices {
+				if snap.PCIeDevices[i].BDF == nil {
+					continue
+				}
+				if sanitizeBDFForLookup(*snap.PCIeDevices[i].BDF) == normalized {
+					mergeComponentStatus(&snap.PCIeDevices[i].HardwareComponentStatus, ts, status, detail)
+				}
+			}
+		case strings.HasPrefix(key, "storage:"):
+			devName := strings.TrimPrefix(key, "storage:")
+			if devName == "all" {
+				for i := range snap.Storage {
+					mergeComponentStatus(&snap.Storage[i].HardwareComponentStatus, ts, status, detail)
+				}
+			} else {
+				for i := range snap.Storage {
+					linuxDev, _ := snap.Storage[i].Telemetry["linux_device"].(string)
+					if filepath.Base(strings.TrimSpace(linuxDev)) == devName {
+						mergeComponentStatus(&snap.Storage[i].HardwareComponentStatus, ts, status, detail)
+					}
+				}
+			}
+		case strings.HasPrefix(key, "memory:"):
+			for i := range snap.Memory {
+				mergeComponentStatus(&snap.Memory[i].HardwareComponentStatus, ts, status, detail)
+			}
+		case strings.HasPrefix(key, "cpu:"):
+			for i := range snap.CPUs {
+				mergeComponentStatus(&snap.CPUs[i].HardwareComponentStatus, ts, status, detail)
+			}
+		}
+	}
+}
+
+// dbStatusToSATStatus converts ComponentStatusDB status strings to the format
+// expected by mergeComponentStatus (which uses "OK", "Warning", "Critical", "Unknown").
+func dbStatusToSATStatus(s string) string {
+	switch strings.TrimSpace(s) {
+	case "OK", "Warning", "Critical", "Unknown":
+		return s
+	default:
+		return ""
+	}
+}
+
+// sanitizeBDFForLookup normalises a PCIe BDF address to a canonical lower-case form
+// suitable for comparison. "c8:00.0" → "0000:c8:00.0"; already-full BDFs are left as-is.
+func sanitizeBDFForLookup(bdf string) string {
+	bdf = strings.ToLower(strings.TrimSpace(bdf))
+	if bdf == "" || bdf == "gpu" || strings.ContainsAny(bdf, " \t") {
+		return ""
+	}
+	if strings.Count(bdf, ":") == 1 {
+		bdf = "0000:" + bdf
+	}
+	return bdf
+}
+
 func ptrString(v *string) string {
 	if v == nil {
 		return ""