fix: replace hard reload with SPA routing in seed phrase reminder

- Replace window.location.href with router.push() for /seed-backup navigation
- Prevents full page reload that was causing app remount and singleton loss
- Maintains singleton persistence and database connection across navigation

This fixes the issue where navigating to seed-backup page via the reminder
modal was triggering a full page reload, causing the PlatformService singleton
to be lost and database to be re-initialized unnecessarily.

src/utils/seedPhraseReminder.ts

@@ -1,4 +1,5 @@
 import { NotificationIface } from "@/constants/app";
+import router from "@/router";
 
 const SEED_REMINDER_KEY = "seedPhraseReminderLastShown";
 const REMINDER_COOLDOWN_MS = 24 * 60 * 60 * 1000; // 24 hours in milliseconds
@@ -53,8 +54,8 @@ export function createSeedReminderNotification(): NotificationIface {
     yesText: "Backup Identifier Seed",
     noText: "Remind me Later",
     onYes: async () => {
-      // Navigate to seed backup page
-      window.location.href = "/seed-backup";
+      // Navigate to seed backup page using SPA routing
+      await router.push({ path: "/seed-backup" });
     },
     onNo: async () => {
       // Mark as shown so it won't appear again for 24 hours