fix for resend, cooldown and a few small fixes

frontend/pweb/lib/providers/two_factor.dart

@@ -22,6 +22,7 @@ class TwoFactorProvider extends ChangeNotifier {
   String? _currentPendingToken;
   Timer? _cooldownTimer;
   int _cooldownRemainingSeconds = 0;
+  DateTime? _cooldownUntil;
 
   FlowStatus get status => _status;
   bool get isSubmitting => _status == FlowStatus.submitting;
@@ -108,48 +109,69 @@ class TwoFactorProvider extends ChangeNotifier {
       return;
     }
 
-    final remaining = pending.cooldownRemainingSeconds;
-    if (remaining <= 0) {
+    final until = pending.cooldownUntil;
+    if (until == null) {
       _stopCooldown(notify: _cooldownRemainingSeconds != 0);
       return;
     }
 
-    if (_cooldownRemainingSeconds != remaining) {
-      _startCooldown(remaining);
+    if (!_isCooldownActive(until) && _cooldownRemainingSeconds != 0) {
+      _stopCooldown(notify: true);
+      return;
+    }
+
+    if (_cooldownUntil == null || _cooldownUntil != until) {
+      _startCooldownUntil(until);
     }
   }
 
   void _startCooldown(int seconds) {
+    final until = DateTime.now().add(Duration(seconds: seconds));
+    _startCooldownUntil(until);
+  }
+
+  void _startCooldownUntil(DateTime until) {
     _cooldownTimer?.cancel();
-    _cooldownRemainingSeconds = seconds;
+    _cooldownUntil = until;
+    _cooldownRemainingSeconds = _cooldownRemaining();
 
     if (_cooldownRemainingSeconds <= 0) {
       _cooldownTimer = null;
+      _cooldownUntil = null;
       notifyListeners();
       return;
     }
 
     _cooldownTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
-      if (_cooldownRemainingSeconds <= 1) {
-        _cooldownRemainingSeconds = 0;
-        _cooldownTimer?.cancel();
-        _cooldownTimer = null;
-        notifyListeners();
+      final remaining = _cooldownRemaining();
+      if (remaining <= 0) {
+        _stopCooldown(notify: true);
         return;
       }
-
-      _cooldownRemainingSeconds -= 1;
-      notifyListeners();
+      if (remaining != _cooldownRemainingSeconds) {
+        _cooldownRemainingSeconds = remaining;
+        notifyListeners();
+      }
     });
 
     notifyListeners();
   }
 
+  bool _isCooldownActive(DateTime until) => until.isAfter(DateTime.now());
+
+  int _cooldownRemaining() {
+    final until = _cooldownUntil;
+    if (until == null) return 0;
+    final remaining = until.difference(DateTime.now()).inSeconds;
+    return remaining < 0 ? 0 : remaining;
+  }
+
   void _stopCooldown({bool notify = false}) {
     _cooldownTimer?.cancel();
     _cooldownTimer = null;
     final hadCooldown = _cooldownRemainingSeconds != 0;
     _cooldownRemainingSeconds = 0;
+    _cooldownUntil = null;
 
     if (notify && hadCooldown) {
       notifyListeners();