Updater for decky-loader (#117)

* Add an updater in settings for decky-loader

* add chmod

* remove junk comments

frontend/src/updater.ts

@@ -0,0 +1,30 @@
+import { sleep } from 'decky-frontend-lib';
+
+export enum Branches {
+  Release,
+  Prerelease,
+  Nightly,
+}
+
+export interface DeckyUpdater {
+  updateProgress: (val: number) => void;
+  finish: () => void;
+}
+
+export async function callUpdaterMethod(methodName: string, args = {}) {
+  const response = await fetch(`http://127.0.0.1:1337/updater/${methodName}`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify(args),
+  });
+
+  return response.json();
+}
+
+export async function finishUpdate() {
+  callUpdaterMethod('do_restart');
+  await sleep(3000);
+  location.reload();
+}