feat: add user groups

backend/internal/dto/user_group_dto.go

@@ -0,0 +1,32 @@
+package dto
+
+import "time"
+
+type UserGroupDtoWithUsers struct {
+	ID           string    `json:"id"`
+	FriendlyName string    `json:"friendlyName"`
+	Name         string    `json:"name"`
+	Users        []UserDto `json:"users"`
+	CreatedAt    time.Time `json:"createdAt"`
+}
+
+type UserGroupDtoWithUserCount struct {
+	ID           string    `json:"id"`
+	FriendlyName string    `json:"friendlyName"`
+	Name         string    `json:"name"`
+	UserCount    int64     `json:"userCount"`
+	CreatedAt    time.Time `json:"createdAt"`
+}
+
+type UserGroupCreateDto struct {
+	FriendlyName string `json:"friendlyName" binding:"required,min=3,max=30"`
+	Name         string `json:"name" binding:"required,min=3,max=30,userGroupName"`
+}
+
+type UserGroupUpdateUsersDto struct {
+	UserIDs []string `json:"userIds" binding:"required"`
+}
+
+type AssignUserToGroupDto struct {
+	UserID string `json:"userId" binding:"required"`
+}