Rework FEP-7888 implementation (#36064)

db/migrate/20250909100506_add_index_on_parent_status_id_to_conversations.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AddIndexOnParentStatusIdToConversations < ActiveRecord::Migration[8.0]
+  disable_ddl_transaction!
+
+  def change
+    add_index :conversations, :parent_status_id, algorithm: :concurrently, unique: true, where: 'parent_status_id IS NOT NULL'
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_09_02_221600) do
+ActiveRecord::Schema[8.0].define(version: 2025_09_09_100506) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_catalog.plpgsql"
 
@@ -361,6 +361,7 @@ ActiveRecord::Schema[8.0].define(version: 2025_09_02_221600) do
     t.datetime "updated_at", precision: nil, null: false
     t.bigint "parent_status_id"
     t.bigint "parent_account_id"
+    t.index ["parent_status_id"], name: "index_conversations_on_parent_status_id", unique: true, where: "(parent_status_id IS NOT NULL)"
     t.index ["uri"], name: "index_conversations_on_uri", unique: true, opclass: :text_pattern_ops, where: "(uri IS NOT NULL)"
   end