DEV: Re-introduce validator

Author: keegangeorge

config/settings.yml

@@ -374,6 +374,7 @@ discourse_ai:
 
   ai_spam_detection_enabled:
     default: false
+    validator: "DiscourseAi::Configuration::SpamDetectionValidator"
   ai_spam_detection_user_id:
     default: ""
     hidden: true

lib/configuration/spam_detection_validator.rb

@@ -10,6 +10,8 @@ def initialize(opts = {})
       def valid_value?(val)
         return true if Rails.env.test?
         return true if AiModerationSetting.spam
+        # only validate when enabling setting
+        return true if val == "f"
 
         false
       end