Convert the whole filesystem UI to Typescript

svelte/src/lib/UserStore.ts

@@ -0,0 +1,13 @@
+import { writable } from "svelte/store";
+import { get_user, type Subscription, type User } from "./PixeldrainAPI";
+
+export const user = writable(
+	{ subscription: {} as Subscription } as User,
+	(set: (value: User) => void) => {
+		get_user().then((u: User) => {
+			set(u)
+		}).catch((err: any) => {
+			alert("Could not fetch user:\n" + JSON.stringify(err))
+		})
+	}
+)