feat: Portal endpoint (#4633)

spec/models/portal_spec.rb

@@ -0,0 +1,16 @@
+require 'rails_helper'
+
+RSpec.describe Portal, type: :model do
+  context 'with validations' do
+    it { is_expected.to validate_presence_of(:account_id) }
+    it { is_expected.to validate_presence_of(:slug) }
+    it { is_expected.to validate_presence_of(:name) }
+  end
+
+  describe 'associations' do
+    it { is_expected.to belong_to(:account) }
+    it { is_expected.to have_many(:categories) }
+    it { is_expected.to have_many(:folders) }
+    it { is_expected.to have_many(:articles) }
+  end
+end