feat: Users API, ownership transfer and removal of the legacy role string

internal/domain/user/userDomain.go

@@ -19,6 +19,9 @@ var ErrUsernameTaken = errors.New("username taken")
 var ErrInvalidLookup = errors.New("invalid user lookup")
 var ErrVerificationEmailNotSent = errors.New("verification email not sent")
 var ErrPasswordTooLong = errors.New("password too long")
+var ErrRoleChanged = errors.New("user role changed concurrently")
+var ErrInvalidTransfer = errors.New("invalid ownership transfer")
+var ErrConfirmationMismatch = errors.New("confirmation email does not match")
 
 const MaxLookupIDs = 100
 
@@ -31,13 +34,6 @@ func ValidatePassword(password string) error {
 	return nil
 }
 
-type Role string
-
-const (
-	RoleOwner Role = "owner"
-	RoleAdmin Role = "admin"
-)
-
 type User struct {
 	ID                      uint32    `json:"id"`
 	Username                string    `json:"username"`
@@ -46,7 +42,6 @@ type User struct {
 	Email                   string    `json:"email"`
 	DisplayName             string    `json:"display_name"`
 	IsVerified              bool      `json:"is_verified"`
-	Role                    Role      `json:"role"`
 	RoleID                  uint32    `json:"role_id"`
 	VerificationCode        string    `json:"verification_code"`
 	VerificationExpiration  time.Time `json:"verification_expiration"`