Add controller to retarget links

So that internal links can skip turbo frames, and external links
open in new pages

app/javascript/controllers/retarget_links_controller.js

@@ -0,0 +1,15 @@
+import { Controller } from "@hotwired/stimulus"
+
+export default class extends Controller {
+  connect() {
+    this.element.querySelectorAll("a").forEach(this.#retargetLink.bind(this))
+  }
+
+  #retargetLink(link) {
+    link.target = this.#targetsSameDomain(link) ? "_top" : "_blank"
+  }
+
+  #targetsSameDomain(link) {
+    return link.href.startsWith(window.location.origin)
+  }
+}