Decouple login modal opening from Angular

app/views/checkout/_authentication.html.haml

@@ -3,17 +3,17 @@
     .small-12.columns.text-center
       %h3.pad-top
         = t :checkout_headline
-  .row.pad-top
-    -if guest_checkout_allowed?
+  .row.pad-top{ "data-controller": "login-modal" }
+    - if guest_checkout_allowed?
       .small-5.columns.text-center
-        %button.primary.expand{"auth" => "login"}
+        %button.primary.expand{ "data-action": "click->login-modal#call" }
           = t :label_login
       .small-2.columns.text-center
         %p.pad-top= "#{t :action_or}"
       .small-5.columns.text-center
         %button.neutral-btn.dark.expand{"ng-click" => "enabled = true"}
           = t :checkout_as_guest
-    -else
+    - else
       .small-6.columns.small-centered
-        %button.primary.expand{"auth" => "login"}
+        %button.primary.expand{ "data-action": "click->login-modal#call" }
           = t :label_login

app/views/shared/menu/_signed_out.html.haml

@@ -1,5 +1,5 @@
-%li#login-link
-  %a{"auth" => "login"}
+%li#login-link{ "data-controller": "login-modal" }
+  %a{"auth": "login", "data-action": "click->login-modal#call" }
     %img{ src: image_pack_path("menu/icn-login.svg") }
     %span
       = t 'label_login'

app/webpacker/controllers/login_modal_controller.js

@@ -0,0 +1,8 @@
+import { Controller } from "stimulus"
+
+export default class extends Controller {
+  call(event) {
+    event.preventDefault()
+    window.dispatchEvent(new Event("login:modal:open"))
+  }
+}