fix: add instance field to backup/snapshot structs for duplicate node names

addresses #476

added Instance field to StorageBackup and GuestSnapshot structs in both
backend and frontend to properly handle nodes with duplicate hostnames.
updated backup and snapshot counting logic to use instance ID instead of
hostname, consistent with the VM/container/storage count fixes.

this completes the fix for #476 - all counts and groupings now use unique
instance IDs instead of hostnames.

frontend-modern/src/components/shared/UnifiedNodeSelector.tsx

@@ -47,7 +47,7 @@ export const UnifiedNodeSelector: Component<UnifiedNodeSelectorProps> = (props)
   const backupCounts = createMemo(() => {
     const counts: Record<string, number> = {};
 
-    // Count PVE backups and snapshots by node
+    // Count PVE backups and snapshots by node instance ID (not hostname)
     const nodes = props.nodes || state.nodes;
     if (nodes) {
       nodes.forEach((node) => {
@@ -56,13 +56,13 @@ export const UnifiedNodeSelector: Component<UnifiedNodeSelectorProps> = (props)
         // Count storage backups (excluding PBS backups which are counted separately)
         if (state.pveBackups?.storageBackups) {
           count += state.pveBackups.storageBackups.filter(
-            (b) => b.node === node.name && !b.isPBS,
+            (b) => b.instance === node.id && !b.isPBS,
           ).length;
         }
 
         // Count snapshots
         if (state.pveBackups?.guestSnapshots) {
-          count += state.pveBackups.guestSnapshots.filter((s) => s.node === node.name).length;
+          count += state.pveBackups.guestSnapshots.filter((s) => s.instance === node.id).length;
         }
 
         counts[node.name] = count;

frontend-modern/src/types/api.ts

@@ -318,6 +318,7 @@ export interface StorageBackup {
   id: string;
   storage: string;
   node: string;
+  instance: string;
   type: string;
   vmid: number;
   time: string;
@@ -343,6 +344,7 @@ export interface GuestSnapshot {
   id: string;
   name: string;
   node: string;
+  instance: string;
   type: string;
   vmid: number;
   time: string;

internal/models/models.go

@@ -374,6 +374,7 @@ type StorageBackup struct {
 	ID           string    `json:"id"`
 	Storage      string    `json:"storage"`
 	Node         string    `json:"node"`
+	Instance     string    `json:"instance"` // Unique instance identifier (for nodes with duplicate names)
 	Type         string    `json:"type"`
 	VMID         int       `json:"vmid"`
 	Time         time.Time `json:"time"`
@@ -393,6 +394,7 @@ type GuestSnapshot struct {
 	ID          string    `json:"id"`
 	Name        string    `json:"name"`
 	Node        string    `json:"node"`
+	Instance    string    `json:"instance"` // Unique instance identifier (for nodes with duplicate names)
 	Type        string    `json:"type"`
 	VMID        int       `json:"vmid"`
 	Time        time.Time `json:"time"`

internal/monitoring/monitor.go

@@ -3247,6 +3247,7 @@ func (m *Monitor) pollStorageBackupsWithNodes(ctx context.Context, instanceName
 					ID:           fmt.Sprintf("%s-%s", instanceName, content.Volid),
 					Storage:      storage.Storage,
 					Node:         backupNode,
+					Instance:     instanceName,
 					Type:         backupType,
 					VMID:         content.VMID,
 					Time:         time.Unix(content.CTime, 0),
@@ -3316,6 +3317,7 @@ func (m *Monitor) pollGuestSnapshots(ctx context.Context, instanceName string, c
 				ID:          fmt.Sprintf("%s-%s-%d-%s", instanceName, vm.Node, vm.VMID, snap.Name),
 				Name:        snap.Name,
 				Node:        vm.Node,
+				Instance:    instanceName,
 				Type:        "qemu",
 				VMID:        vm.VMID,
 				Time:        time.Unix(snap.SnapTime, 0),
@@ -3358,6 +3360,7 @@ func (m *Monitor) pollGuestSnapshots(ctx context.Context, instanceName string, c
 				ID:          fmt.Sprintf("%s-%s-%d-%s", instanceName, ct.Node, ct.VMID, snap.Name),
 				Name:        snap.Name,
 				Node:        ct.Node,
+				Instance:    instanceName,
 				Type:        "lxc",
 				VMID:        ct.VMID,
 				Time:        time.Unix(snap.SnapTime, 0),