feat: add error message if org doesn't own stock

app/controllers/organisation_relationships_controller.rb

@@ -51,6 +51,11 @@ class OrganisationRelationshipsController < ApplicationController
         @organisations = Organisation.where.not(id: child_organisation.id).pluck(:id, :name)
         render "organisation_relationships/add_housing_provider"
         return
+      elsif !parent_organisation.holds_own_stock
+        @organisation.errors.add :related_organisation_id, I18n.t("validations.scheme.owning_organisation.does_not_own_stock")
+        @organisations = Organisation.where.not(id: child_organisation.id).pluck(:id, :name)
+        render "organisation_relationships/add_housing_provider"
+        return
       end
     end
     create!(child_organisation:, parent_organisation:)

db/schema.rb

@@ -398,9 +398,9 @@ ActiveRecord::Schema[7.0].define(version: 2022_12_06_081127) do
     t.integer "inc1mort"
     t.integer "income2"
     t.integer "income2nk"
-    t.integer "prevown"
     t.integer "savingsnk"
     t.integer "savings"
+    t.integer "prevown"
     t.string "sex3"
     t.index ["created_by_id"], name: "index_sales_logs_on_created_by_id"
     t.index ["managing_organisation_id"], name: "index_sales_logs_on_managing_organisation_id"