refactor(trading): rename 卖出相关 黑洞 to 积分股池

- Update 10% 进入黑洞 to 10% 进入积分股池
- Update 销毁金额 to 进入积分股池 in sell confirmation
- Update 注意 text in sell confirmation
- Change color from red to green for 积分股池 text

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mining-app/lib/presentation/pages/trading/trading_page.dart

@@ -507,10 +507,10 @@ class _TradingPageState extends ConsumerState<TradingPage> {
                     style: TextStyle(fontSize: 12, color: _grayText),
                   ),
                   Text(
-                    '10% 进入黑洞',
+                    '10% 进入积分股池',
                     style: TextStyle(
                       fontSize: 12,
-                      color: _red,
+                      color: _green,
                       fontFamily: 'monospace',
                     ),
                   ),
@@ -928,8 +928,8 @@ class _TradingPageState extends ConsumerState<TradingPage> {
               Text('交易总额: ${formatAmount(total.toString())} 积分值'),
               const SizedBox(height: 8),
               Text(
-                '销毁金额: ${formatAmount(burned.toString())} 积分值 (10%)',
-                style: const TextStyle(color: _red),
+                '进入积分股池: ${formatAmount(burned.toString())} 积分值 (10%)',
+                style: const TextStyle(color: _green),
               ),
               const SizedBox(height: 8),
               Text(
@@ -941,7 +941,7 @@ class _TradingPageState extends ConsumerState<TradingPage> {
               ),
               const SizedBox(height: 16),
               const Text(
-                '注意: 卖出积分股将扣除10%进入黑洞销毁，此操作不可撤销。',
+                '注意: 卖出积分股将扣除10%进入积分股池，此操作不可撤销。',
                 style: TextStyle(
                   fontSize: 12,
                   color: _grayText,