feat: stage edits to published articles as drafts (#14842)

app/controllers/api/v1/accounts/articles_controller.rb

@@ -30,8 +30,8 @@ class Api::V1::Accounts::ArticlesController < Api::V1::Accounts::BaseController
   end
 
   def update
-    @article.update!(article_params) if params[:article].present?
-    render json: { error: @article.errors.messages }, status: :unprocessable_entity and return unless @article.valid?
+    persist_article_changes if params[:article].present?
+    render json: { message: @article.errors.full_messages.to_sentence }, status: :unprocessable_entity and return unless @article.valid?
   end
 
   def destroy
@@ -67,12 +67,26 @@ class Api::V1::Accounts::ArticlesController < Api::V1::Accounts::BaseController
     @portal ||= Current.account.portals.find_by!(slug: params[:portal_id])
   end
 
+  # Draft-only autosaves must not bump the public-facing updated_at, so write
+  # them with update_columns (which skips the timestamp). update_columns also
+  # skips validations, so assign and validate first to avoid persisting content
+  # that exceeds the column length limit.
+  def persist_article_changes
+    keys = article_params.to_h.keys
+    if keys.any? && (keys - %w[draft_title draft_content]).empty?
+      @article.assign_attributes(article_params)
+      @article.update_columns(article_params.to_h) if @article.valid? # rubocop:disable Rails/SkipsModelValidations
+    else
+      @article.update!(article_params)
+    end
+  end
+
   def article_params
     params.require(:article).permit(
       :title, :slug, :position, :content, :description, :category_id, :author_id, :associated_article_id, :status,
-      :locale, meta: [:title,
-                      :description,
-                      { tags: [] }]
+      :locale, :draft_title, :draft_content, meta: [:title,
+                                                    :description,
+                                                    { tags: [] }]
     )
   end