Move dialog focus handling to a stimulus controller

... for template caching

app/javascript/controllers/dialog_focus_controller.js

@@ -0,0 +1,16 @@
+import { Controller } from "@hotwired/stimulus"
+import { isTouchDevice } from "helpers/platform_helpers"
+
+export default class extends Controller {
+  static targets = [ "mouse", "touch" ]
+
+  connect() {
+    this.#setup()
+  }
+
+  #setup() {
+    const touch = isTouchDevice()
+    if (this.hasMouseTarget) this.mouseTarget.autofocus = !touch
+    if (this.hasTouchTarget) this.touchTarget.autofocus = touch
+  }
+}