fix(setting): ensure DefaultRole stores role ID while exposing role

name in APIs (fix/settings-get-role)

- Simplify initial settings to use `model.GUEST` as the default role ID
  instead of querying roles at startup.
- Update `GetSetting`, `ListSettings` handlers to:
  - Convert stored role ID into the corresponding role name when
    returning data.
  - Preserve dynamic role options for selection.
- Remove unused `strings` import and role preloading logic from
  `InitialSettings`.
- Avoid DB dependency during initialization while keeping consistent
  role display for frontend clients.

internal/op/hook.go

@@ -88,12 +88,12 @@ var settingItemHooks = map[string]SettingItemHook{
 		if v == "" {
 			return nil
 		}
-		r, err := GetRoleByName(v)
+		id, err := strconv.Atoi(v)
 		if err != nil {
-			return err
+			return errors.WithStack(err)
 		}
-		item.Value = strconv.Itoa(int(r.ID))
-		return nil
+		_, err = GetRole(uint(id))
+		return err
 	},
 }
 

server/handles/setting.go

@@ -19,9 +19,12 @@ func getRoleOptions() string {
 	if err != nil {
 		return ""
 	}
-	names := make([]string, len(roles))
-	for i, r := range roles {
-		names[i] = r.Name
+	names := make([]string, 0, len(roles))
+	for _, r := range roles {
+		if r.Name == "admin" || r.Name == "guest" {
+			continue
+		}
+		names = append(names, r.Name)
 	}
 	return strings.Join(names, ",")
 }
@@ -85,6 +88,22 @@ func SaveSettings(c *gin.Context) {
 		common.ErrorResp(c, err, 400)
 		return
 	}
+
+	for i := range req {
+		if req[i].Key == conf.DefaultRole {
+			role, err := op.GetRoleByName(req[i].Value)
+			if err != nil {
+				common.ErrorResp(c, err, 400)
+				return
+			}
+			if role.Name == "admin" || role.Name == "guest" {
+				common.ErrorStrResp(c, "cannot set admin or guest as default role", 400)
+				return
+			}
+			req[i].Value = strconv.Itoa(int(role.ID))
+		}
+	}
+
 	if err := op.SaveSettingItems(req); err != nil {
 		common.ErrorResp(c, err, 500)
 	} else {