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/webui/server.go

@@ -164,6 +164,8 @@ type handler struct {
 	// pending network change (rollback on timeout)
 	pendingNet   *pendingNetChange
 	pendingNetMu sync.Mutex
+	// kmsg hardware error watcher
+	kmsg *kmsgWatcher
 }
 
 // NewHandler creates the HTTP mux with all routes.
@@ -203,6 +205,13 @@ func NewHandler(opts HandlerOptions) http.Handler {
 	}
 	h.startMetricsCollector()
 
+	// Start kmsg hardware error watcher if the app (and its status DB) is available.
+	if opts.App != nil {
+		h.kmsg = newKmsgWatcher(opts.App.StatusDB)
+		h.kmsg.start()
+		globalQueue.kmsgWatcher = h.kmsg
+	}
+
 	globalQueue.startWorker(&opts)
 	mux := http.NewServeMux()