Add basic frontend structure

frontend/src/lib/persistent-store.ts

@@ -0,0 +1,23 @@
+import { writable } from 'svelte/store'
+
+interface PersistedSettings {
+  darkmode: boolean
+  loggedIn: boolean
+  friendlyName: string
+  email: string
+  role: string
+  refreshToken: string
+}
+
+const settingsDefault: PersistedSettings = {
+  darkmode: false,
+  loggedIn: false,
+  friendlyName: "",
+  email: "",
+  role: "member",
+  refreshToken: ""
+}
+
+export const persistentSettings = writable<PersistedSettings>(JSON.parse(localStorage.getItem('persistentSettings') || JSON.stringify(settingsDefault)))
+
+persistentSettings.subscribe((value) => localStorage.persistentSettings = JSON.stringify(value))