feat(ntfy): add ntfy fields to admin_users and ntfy_configured? method

app/models/admin_user.rb

@@ -1,11 +1,23 @@
 class AdminUser < ApplicationRecord
   has_secure_password
 
-  validates :email, presence: true, uniqueness: true, format: { with: URI::MailTo::EMAIL_REGEXP }
+  validates :email, presence: true, uniqueness: { case_sensitive: false }, format: { with: URI::MailTo::EMAIL_REGEXP }
   validates :name, presence: true
   validates :password, length: { minimum: 8 }, if: -> { password.present? }
 
+  before_validation :normalize_email
+
   def update_last_login!
     update!(last_login_at: Time.current)
   end
+
+  def ntfy_configured?
+    ntfy_enabled? && ntfy_topic.present? && ntfy_token.present?
+  end
+
+  private
+
+  def normalize_email
+    self.email = email&.downcase&.strip
+  end
 end