feat: add liner integration

app/controllers/api/v1/accounts/integrations/linear_controller.rb

@@ -0,0 +1,22 @@
+class Api::V1::Accounts::Integrations::LinearController < Api::V1::Accounts::BaseController
+  before_action :fetch_conversation, only: [:list]
+
+  def list
+    issues = linear_processor_service.list_issues
+    render json: issues, status: :ok
+  end
+
+  private
+
+  def linear_processor_service
+    Integrations::Linear::ProcessorService.new(account: Current.account, conversation: @conversation)
+  end
+
+  def permitted_params
+    params.permit(:conversation_id)
+  end
+
+  def fetch_conversation
+    @conversation = Current.account.conversations.find_by!(display_id: permitted_params[:conversation_id])
+  end
+end