Refactor captcha validation per review feedback

- Extract validation into checkMultipleCaptchaProviders function
- Use providerItem.Provider instead of DB lookup
- Add i18n wrapper for error message
- Include provider names in error message

Co-authored-by: hsluoyz <3787410+hsluoyz@users.noreply.github.com>

object/application.go

@@ -669,6 +669,21 @@ func GetAllowedApplications(applications []*Application, userId string, lang str
 	return res, nil
 }
 
+func checkMultipleCaptchaProviders(application *Application, lang string) error {
+	var captchaProviders []string
+	for _, providerItem := range application.Providers {
+		if providerItem.Provider != nil && providerItem.Provider.Category == "Captcha" {
+			captchaProviders = append(captchaProviders, providerItem.Name)
+		}
+	}
+
+	if len(captchaProviders) > 1 {
+		return fmt.Errorf(i18n.Translate(lang, "general:Multiple captcha providers are not allowed in the same application: %s"), strings.Join(captchaProviders, ", "))
+	}
+
+	return nil
+}
+
 func UpdateApplication(id string, application *Application, isGlobalAdmin bool, lang string) (bool, error) {
 	owner, name, err := util.GetOwnerAndNameFromIdWithError(id)
 	if err != nil {
@@ -707,6 +722,11 @@ func UpdateApplication(id string, application *Application, isGlobalAdmin bool,
 		return false, fmt.Errorf("only applications belonging to built-in organization can be shared")
 	}
 
+	err = checkMultipleCaptchaProviders(application, lang)
+	if err != nil {
+		return false, err
+	}
+
 	for _, providerItem := range application.Providers {
 		providerItem.Provider = nil
 	}

web/src/table/ProviderTable.js

@@ -90,10 +90,7 @@ class ProviderTable extends React.Component {
                 }
               }} >
               {
-                Setting.getDeduplicatedArray(this.props.providers, table, "name").filter(provider => provider.category !== "Captcha" || !table.some(tableItem => {
-                  const existingProvider = Setting.getArrayItem(this.props.providers, "name", tableItem.name);
-                  return existingProvider && existingProvider.category === "Captcha";
-                })).map((provider, index) => (
+                Setting.getDeduplicatedArray(this.props.providers, table, "name").map((provider, index) => (
                   <Option key={index} value={provider.name} label={`${provider.name} ${provider.displayName || ""}`}>
                     <div style={{display: "flex", alignItems: "center", gap: "8px"}}>
                       <img width={20} height={20} src={Setting.getProviderLogoURL(provider)} alt={provider.type} />