feat: add push notification settings to user profile and update related functionality

frontend/vue-app/src/services/pushSubscription.ts

@@ -186,3 +186,25 @@ export async function isSubscribedToPush(): Promise<boolean> {
     return false
   }
 }
+
+/** localStorage key used to persist the user's explicit push opt-out across logins. */
+const PUSH_OPT_OUT_KEY = 'push_opt_out'
+
+/**
+ * Persist or clear the user's push opt-out preference in localStorage.
+ * Call with `true` when the user disables push, `false` when they enable it.
+ */
+export function setPushOptOut(optOut: boolean): void {
+  if (optOut) {
+    localStorage.setItem(PUSH_OPT_OUT_KEY, '1')
+  } else {
+    localStorage.removeItem(PUSH_OPT_OUT_KEY)
+  }
+}
+
+/**
+ * Returns true if the user has explicitly opted out of push notifications.
+ */
+export function isPushOptedOut(): boolean {
+  return localStorage.getItem(PUSH_OPT_OUT_KEY) === '1'
+}