feat: expose assignable conversation owners

spec/controllers/api/v1/accounts/inboxes_controller_spec.rb

@@ -251,6 +251,28 @@ RSpec.describe 'Inboxes API', type: :request do
     end
   end
 
+  describe 'GET /api/v1/accounts/{account.id}/inboxes/{inbox.id}/assignable_owners' do
+    let(:inbox) { create(:inbox, account: account) }
+    let!(:account_bot) { create(:agent_bot, account: account, name: 'Account bot') }
+    let!(:global_bot) { create(:agent_bot, account: nil, name: 'Global bot') }
+
+    before do
+      create(:inbox_member, user: agent, inbox: inbox)
+    end
+
+    it 'returns assignable agents and accessible agent bots' do
+      get "/api/v1/accounts/#{account.id}/inboxes/#{inbox.id}/assignable_owners",
+          headers: admin.create_new_auth_token,
+          as: :json
+
+      expect(response).to have_http_status(:success)
+
+      response_data = response.parsed_body['payload']
+      expect(response_data.pluck('assignee_type')).to include('User', 'AgentBot')
+      expect(response_data.pluck('name')).to include(agent.name, admin.name, account_bot.name, global_bot.name)
+    end
+  end
+
   describe 'GET /api/v1/accounts/{account.id}/inboxes/{inbox.id}/campaigns' do
     let(:inbox) { create(:inbox, account: account) }