overall ui bugfixes and hivemind improvements

lib/logic/ad_manager.dart

@@ -94,8 +94,8 @@ class AdManager extends ChangeNotifier {
     final keys = await CryptoService.getOrCreateKeys();
     final pubKey = keys['publicKey']!;
 
-    // 3. Attach custom data to the ad so Google sends it back to our Hivemind server
-    _rewardedAd!.serverSideVerificationOptions = ServerSideVerificationOptions(
+    // 3. Build SSV options to send to our Hivemind server via Google's callback
+    final ssvOptions = ServerSideVerificationOptions(
       customData: jsonEncode({
         'device_id': deviceId,
         'public_key': pubKey,
@@ -130,7 +130,8 @@ class AdManager extends ChangeNotifier {
       },
     );
 
-    // 5. Show the ad
+    // 5. Show the ad with SSV options
+    _rewardedAd!.setServerSideOptions(ssvOptions);
     await _rewardedAd!.show(
       onUserEarnedReward: (AdWithoutView ad, RewardItem reward) {
         debugPrint('[AdManager] Reward earned: ${reward.amount} ${reward.type}');

lib/logic/session_timer.dart

@@ -182,6 +182,7 @@ class SessionTimer extends ChangeNotifier {
   @override
   void dispose() {
     _timer?.cancel();
+    VpnNotificationManager.cancel();
     super.dispose();
   }
 }

lib/logic/vpn_connection.dart

@@ -156,7 +156,7 @@ class VpnConnection extends ChangeNotifier {
       return false;
     }
 
-    // ── Step 2: Start the WireGuard tunnel with the fetched config ─────────
+    // ── Step 3: Start the WireGuard tunnel with the fetched config ─────────
     try {
       // Re-initialize to ensure VPN permission is granted before starting
       await _wireguard.initialize(interfaceName: 'Paladin0');