fix(StockChart): 图表组件使用 aspect-ratio 保持宽高比，统一弹窗大小

- KLineChartModal: 日K线图使用 aspectRatio 替代固定高度
- StockChartKLineModal: K线图高度改为响应式 min(400px, 60vh)
- TimelineChartModal: 分时图弹窗大小与日K线统一，maxWidth: 1400px

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/components/StockChart/KLineChartModal.tsx

@@ -705,7 +705,7 @@ const KLineChartModal: React.FC<KLineChartModalProps> = ({
             </div>
           )}
 
-          <div style={{ position: 'relative', height: isMobile ? '450px' : '680px', width: '100%' }}>
+          <div style={{ position: 'relative', width: '100%' }}>
             {loading && (
               <div
                 style={{
@@ -736,7 +736,8 @@ const KLineChartModal: React.FC<KLineChartModalProps> = ({
                 <span style={{ color: '#e0e0e0' }}>加载K线数据...</span>
               </div>
             )}
-            <div ref={chartRef} style={{ width: '100%', height: '100%' }} />
+            {/* 使用 aspect-ratio 保持图表宽高比，K线图推荐 2.5:1 */}
+            <div ref={chartRef} style={{ width: '100%', aspectRatio: isMobile ? '1.8 / 1' : '2.5 / 1', minHeight: isMobile ? '280px' : '400px' }} />
           </div>
         </div>
       </div>