refactor: group uuid instead of index

internal/model/report/ship.go

@@ -1,5 +1,7 @@
 package report
 
+import "github.com/google/uuid"
+
 type ShipClass struct {
 	Name     string `json:"name"`
 	Drive    Float  `json:"drive"`
@@ -34,9 +36,9 @@ type IncomingGroup struct {
 
 type LocalGroup struct {
 	OtherGroup
-	Index uint    `json:"index"`
-	State string  `json:"state"`
-	Fleet *string `json:"fleet"`
+	ID    uuid.UUID `json:"id"`
+	State string    `json:"state"`
+	Fleet *string   `json:"fleet"`
 }
 
 type OtherGroup struct {