FEATURE: encourage users to set chat thread titles (#26617)

This change encourages users to title their threads to make it easier for other users to join in on conversations that matter to them.

The creator of the chat thread will receive a toast notification prompting them to add a thread title when on mobile and the thread has at least 5 sent replies.

plugins/chat/db/migrate/20240409060201_add_thread_title_prompt_to_user_chat_thread_memberships.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class AddThreadTitlePromptToUserChatThreadMemberships < ActiveRecord::Migration[7.0]
+  def change
+    add_column :user_chat_thread_memberships,
+               :thread_title_prompt_seen,
+               :boolean,
+               default: false,
+               null: false
+  end
+end

plugins/chat/db/migrate/20240409093348_add_show_thread_title_prompts_to_user_options.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddShowThreadTitlePromptsToUserOptions < ActiveRecord::Migration[7.0]
+  def change
+    add_column :user_options, :show_thread_title_prompts, :boolean, default: true, null: false
+  end
+end