Add store for UUID and conditional loading of the LDB page for public/staff boards

src/lib/stores/uuid.js

@@ -0,0 +1,23 @@
+import { writable } from 'svelte/store'
+import { browser } from '$app/environment';
+
+export const uuid = writable(fromLocalStorage('uuid', null))
+toLocalStorage(uuid, 'uuid');
+
+function fromLocalStorage(storageKey, fallback) {
+    if (browser) {
+        const storedValue = localStorage.getItem(storageKey);
+        if (storedValue !== 'undefined') {
+            return storedValue
+        }
+    }
+    return fallback
+}
+
+function toLocalStorage(store, storageKey) {
+    if (browser) {
+        store.subscribe(value => {
+            localStorage.setItem(storageKey, value)
+        })
+    }
+}