persist error count aside from errors (#2652)

#### Does this PR need a docs update or release note?

- [ ] ⛔ No

#### Type of change

- [x] 🐛 Bugfix

#### Issue(s)

* #1970

src/pkg/backup/backup.go

@@ -38,6 +38,7 @@ type Backup struct {
 
 	// Errors contains all errors aggregated during a backup operation.
 	Errors     fault.ErrorsData `json:"errors"`
+	ErrorCount int              `json:"errorCount"`
 
 	// stats are embedded so that the values appear as top-level properties
 	stats.Errs // Deprecated, replaced with Errors.
@@ -56,6 +57,13 @@ func New(
 	se stats.StartAndEndTime,
 	errs *fault.Errors,
 ) *Backup {
+	errData := errs.Data()
+
+	errCount := len(errs.Data().Errs)
+	if errData.Err != nil {
+		errCount++
+	}
+
 	return &Backup{
 		BaseModel: model.BaseModel{
 			ID: id,
@@ -68,7 +76,8 @@ func New(
 		DetailsID:       detailsID,
 		Status:          status,
 		Selector:        selector,
-		Errors:          errs.Data(),
+		Errors:          errData,
+		ErrorCount:      errCount,
 		ReadWrites:      rw,
 		StartAndEndTime: se,
 		Version:         version.Backup,
@@ -114,7 +123,7 @@ type Printable struct {
 func (b Backup) MinimumPrintable() any {
 	return Printable{
 		ID:            b.ID,
-		ErrorCount:    b.errorCount(),
+		ErrorCount:    b.countErrors(),
 		StartedAt:     b.StartedAt,
 		Status:        b.Status,
 		Version:       "0",
@@ -138,7 +147,7 @@ func (b Backup) Headers() []string {
 // Values returns the values matching the Headers list for printing
 // out to a terminal in a columnar display.
 func (b Backup) Values() []string {
-	status := fmt.Sprintf("%s (%d errors)", b.Status, b.errorCount())
+	status := fmt.Sprintf("%s (%d errors)", b.Status, b.countErrors())
 
 	return []string{
 		common.FormatTabularDisplayTime(b.StartedAt),
@@ -148,8 +157,11 @@ func (b Backup) Values() []string {
 	}
 }
 
-func (b Backup) errorCount() int {
-	var errCount int
+func (b Backup) countErrors() int {
+	errCount := b.ErrorCount
+	if errCount > 0 {
+		return errCount
+	}
 
 	// current tracking
 	if b.ReadErrors != nil || b.WriteErrors != nil {