multiple payout page and small fixes

frontend/pweb/lib/utils/error/handler.dart

@@ -16,6 +16,14 @@ class ErrorHandler {
       'unauthorized': locs.errorLoginUnauthorized,
       'verification_token_not_found': locs.errorVerificationTokenNotFound,
       'internal_error': locs.errorInternalError,
+      'invalid_target': locs.errorInvalidTarget,
+      'pending_token_required': locs.errorPendingTokenRequired,
+      'missing_destination': locs.errorMissingDestination,
+      'missing_code': locs.errorMissingCode,
+      'missing_session': locs.errorMissingSession,
+      'token_expired': locs.errorTokenExpired,
+      'code_attempts_exceeded': locs.errorCodeAttemptsExceeded,
+      'too_many_requests': locs.errorTooManyRequests,
 
       'data_conflict': locs.errorDataConflict,
       'access_denied': locs.errorAccessDenied,

frontend/pweb/lib/utils/error/snackbar.dart

@@ -15,18 +15,23 @@ Future<void> notifyUserOfErrorX({
   int delaySeconds = 3,
 }) async {
   if (!context.mounted) return;
+  if (!_shouldShowError(errorSituation, exception)) {
+    return;
+  }
   final localizedError = ErrorHandler.handleErrorLocs(appLocalizations, exception);
   final technicalDetails = exception.toString();
   final scaffoldMessenger = ScaffoldMessenger.maybeOf(context);
 
   if (scaffoldMessenger != null) {
+    final durationSeconds = _normalizeDelaySeconds(delaySeconds);
+    scaffoldMessenger.clearSnackBars();
     final snackBar = _buildMainErrorSnackBar(
       errorSituation: errorSituation,
       localizedError: localizedError,
       technicalDetails: technicalDetails,
       loc: appLocalizations,
       scaffoldMessenger: scaffoldMessenger,
-      delaySeconds: delaySeconds,
+      delaySeconds: durationSeconds,
     );
     scaffoldMessenger.showSnackBar(snackBar);
     return;
@@ -46,15 +51,20 @@ void showErrorSnackBar({
   required AppLocalizations appLocalizations,
   int delaySeconds = 3,
 }) {
+  if (!_shouldShowError(errorSituation, exception)) {
+    return;
+  }
   final localizedError = ErrorHandler.handleErrorLocs(appLocalizations, exception);
   final technicalDetails = exception.toString();
+  final durationSeconds = _normalizeDelaySeconds(delaySeconds);
+  scaffoldMessenger.clearSnackBars();
   final snackBar = _buildMainErrorSnackBar(
     errorSituation: errorSituation,
     localizedError: localizedError,
     technicalDetails: technicalDetails,
     loc: appLocalizations,
     scaffoldMessenger: scaffoldMessenger,
-    delaySeconds: delaySeconds,
+    delaySeconds: durationSeconds,
   );
   scaffoldMessenger.showSnackBar(snackBar);
 }
@@ -139,19 +149,22 @@ SnackBar _buildMainErrorSnackBar({
   int delaySeconds = 3,
 }) =>
     SnackBar(
-      duration: Duration(seconds: delaySeconds),
+      duration: Duration(seconds: _normalizeDelaySeconds(delaySeconds)),
       content: ErrorSnackBarContent(
         situation: errorSituation,
         localizedError: localizedError,
       ),
       action: SnackBarAction(
         label: loc.showDetailsAction,
-        onPressed: () => scaffoldMessenger.showSnackBar(
-          SnackBar(
-            content: Text(technicalDetails),
-            duration: const Duration(seconds: 6),
-          ),
-        ),
+        onPressed: () {
+          scaffoldMessenger.hideCurrentSnackBar();
+          scaffoldMessenger.showSnackBar(
+            SnackBar(
+              content: Text(technicalDetails),
+              duration: const Duration(seconds: 6),
+            ),
+          );
+        },
       ),
     );
 
@@ -176,3 +189,27 @@ Future<void> _showErrorDialog(
     ),
   );
 }
+
+int _normalizeDelaySeconds(int delaySeconds) =>
+    delaySeconds <= 0 ? 3 : delaySeconds;
+
+String? _lastErrorSignature;
+DateTime? _lastErrorShownAt;
+const int _errorCooldownSeconds = 60;
+
+bool _shouldShowError(String errorSituation, Object exception) {
+  final signature = '$errorSituation|${exception.runtimeType}|${exception.toString()}';
+  final now = DateTime.now();
+
+  if (_lastErrorSignature == signature) {
+    final lastShownAt = _lastErrorShownAt;
+    if (lastShownAt != null &&
+        now.difference(lastShownAt).inSeconds < _errorCooldownSeconds) {
+      return false;
+    }
+  }
+
+  _lastErrorSignature = signature;
+  _lastErrorShownAt = now;
+  return true;
+}