Extract Leftbar and Add Tag controllers

assets/controllers/add_tag_controller.js

@@ -0,0 +1,13 @@
+import { Controller } from '@hotwired/stimulus';
+
+export default class extends Controller {
+  static targets = ['input'];
+
+  toggle() {
+    this.element.classList.toggle('hidden');
+
+    if (!this.element.classList.contains('hidden')) {
+      this.inputTarget.focus();
+    }
+  }
+}

assets/controllers/leftbar_controller.js

@@ -0,0 +1,7 @@
+import { Controller } from '@hotwired/stimulus';
+
+export default class extends Controller {
+  toggleAddTagForm() {
+    this.dispatch('toggleAddTagForm');
+  }
+}