v0.94.0: serialize per-disk SMART into the /disks payload

Additive, backward-compatible (MinAgent floor unchanged). The SMART is already
computed on the request path (storage.Observe -> enrich); this copies the target's
Smart into localapi.DiskInfo (pointer, omitempty) only when Health != "", so an
unread/absent summary stays omitted and the controller renders "Nincs adat".
No new smartctl load, endpoint, or sudoers change.

Test TestDisks_SmartSerialized + red-proof (drop the copy -> fails).

internal/localapi/disks.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 	"time"
 
+	"gitea.dooplex.hu/admin/felhom-agent/internal/hub"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/proxmox"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/storage"
 )
@@ -151,6 +152,12 @@ type DiskInfo struct {
 	// at GuestPath (a host mount-table check) — i.e. live + usable in the guest in the intermediary model.
 	// The controller's drive-absent gate + auto-restart key on this (and State).
 	BoundUnderParent bool `json:"bound_under_parent"`
+	// Smart is the already-computed per-disk SMART health summary (v0.94.0), serialized here so the
+	// controller can render a disk-health card + degradation alert WITHOUT any new smartctl load — the
+	// value is copied straight from the target's Observe-time enrichment. omitempty + a pointer so a
+	// device that exposes no SMART (USB bridge, unread) is ABSENT, not a misleading zero-value UNKNOWN;
+	// the controller feature-detects presence and renders "Nincs adat" when nil (never alarms).
+	Smart *hub.SmartSummary `json:"smart,omitempty"`
 }
 
 // handleDisks lists the host's drives + data-bearing flags (read-only/benign).
@@ -206,6 +213,13 @@ func (s *Server) handleDisks(w http.ResponseWriter, r *http.Request, vmid int) {
 				di.WipeDurableID = wid
 			}
 		}
+		// v0.94.0: surface the already-computed SMART only when it was actually read (Health set).
+		// A zero-value summary (enrich skipped / no smartctl device) has Health "" → stays omitted, so
+		// the controller sees "absent" and renders "Nincs adat" rather than a false UNKNOWN.
+		if t.Smart.Health != "" {
+			sm := t.Smart
+			di.Smart = &sm
+		}
 		out = append(out, di)
 	}
 	// Impl-2a: union in registry+units drives that Observe() does NOT surface (a drive with no PVE