fix(api): relax account password validation

backend/api/internal/logic/common/base.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"reflect"
 	"strings"
+	"unicode/utf8"
 
 	"git.apinb.com/bsm-sdk/core/errcode"
 	"git.apinb.com/bsm-sdk/core/infra"
@@ -16,6 +17,14 @@ import (
 	"gorm.io/gorm"
 )
 
+// AccountPasswordMinLength 是账号密码允许的最低字符数。
+const AccountPasswordMinLength = 6
+
+// IsValidAccountPassword 仅校验账号密码的最低字符长度。
+func IsValidAccountPassword(password string) bool {
+	return utf8.RuneCountInString(password) >= AccountPasswordMinLength
+}
+
 // PasswordHash creates the shared password representation used by account modules.
 func PasswordHash(password string) (string, error) {
 	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)