feat: cleaning code

lib/core/widgets/rank_badge.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/material.dart';
 
+import '../theme/app_theme.dart';
+
 /// نشانِ رتبه (برنز/نقره/طلا/الماس/پادشاه) با رنگ و برچسبِ فارسی.
 class RankBadge extends StatelessWidget {
   final String tier; // bronze..king
@@ -10,7 +12,7 @@ class RankBadge extends StatelessWidget {
   static const _tiers = {
     'bronze': ('برنز', [Color(0xFFCD7F32), Color(0xFF8C5A2B)]),
     'silver': ('نقره', [Color(0xFFBFC6CC), Color(0xFF8A949B)]),
-    'gold': ('طلا', [Color(0xFFFFD54F), Color(0xFFB8860B)]),
+    'gold': ('طلا', [Color(0xFFFFD54F), AppColors.goldDark]),
     'diamond': ('الماس', [Color(0xFF5BE0E6), Color(0xFF1E8A99)]),
     'king': ('پادشاه', [Color(0xFFB388FF), Color(0xFF6A1B9A)]),
   };