Added Localizations and ran small fixes

frontend/pweb/lib/widgets/sidebar/user.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 
 import 'package:pweb/widgets/sidebar/destinations.dart';
 
+import 'package:pweb/generated/i18n/app_localizations.dart';
+
 
 class UserProfileCard extends StatelessWidget {
   final ThemeData theme;
@@ -21,6 +23,7 @@ class UserProfileCard extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final loc = AppLocalizations.of(context)!;
     bool isSelected = selected == PayoutDestination.settings; 
     final backgroundColor = isSelected
         ? theme.colorScheme.primaryContainer
@@ -52,7 +55,7 @@ class UserProfileCard extends StatelessWidget {
               const SizedBox(width: 8),
               Flexible(
                 child: Text(
-                  userName ?? 'User Name',
+                  userName ?? loc.userNamePlaceholder,
                   style: theme.textTheme.bodyLarge?.copyWith(
                     fontSize: 20,
                     fontWeight: FontWeight.w500,
@@ -67,4 +70,4 @@ class UserProfileCard extends StatelessWidget {
       ),
     );
   }
-}
+}