fix(kline): auto-load more history when data doesn't fill screen

- Always assume hasMoreHistory=true on initial load
- Auto-trigger loadMoreHistory when klines don't fill drawable area
- This ensures sparse data periods load all available history

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

.claude/settings.local.json

@@ -790,7 +790,8 @@
       "Bash(ssh -o ProxyJump=ceshi@103.39.231.231 ceshi@192.168.1.111 \"ls -la /home/ceshi/rwadurian/backend/\")",
       "Bash(ssh -o ProxyJump=ceshi@103.39.231.231 ceshi@192.168.1.111 \"ls -la /home/ceshi/rwadurian/backend/services/\")",
       "Bash(where:*)",
-      "Bash(npx md-to-pdf:*)"
+      "Bash(npx md-to-pdf:*)",
+      "Bash(ssh -J ceshi@103.39.231.231 ceshi@192.168.1.111 \"curl -s ''http://localhost:3000/api/price/klines?period=1h&limit=5'' | head -500\")"
     ],
     "deny": [],
     "ask": []

frontend/mining-app/lib/presentation/providers/trading_providers.dart

@@ -113,7 +113,7 @@ class KlinesNotifier extends StateNotifier<KlinesState> {
         state = state.copyWith(
           klines: klines,
           isLoading: false,
-          hasMoreHistory: klines.length >= 100, // 如果返回100条，可能还有更多
+          hasMoreHistory: true, // 默认还有更多历史，直到加载返回空数据
         );
         _startAutoRefresh(apiPeriod);
       },

frontend/mining-app/lib/presentation/widgets/kline_chart/kline_chart_widget.dart

@@ -97,6 +97,24 @@ class _KlineChartWidgetState extends State<KlineChartWidget> {
 
     // 计算滚动位置，让最新K线在屏幕中心
     _scrollToCenter();
+
+    // 如果数据不足以填满屏幕且还有更多历史数据，自动加载更多
+    _checkAndLoadMoreIfNeeded();
+  }
+
+  /// 检查是否需要自动加载更多历史数据
+  void _checkAndLoadMoreIfNeeded() {
+    if (!widget.hasMoreHistory || widget.isLoadingMore) return;
+
+    const leftPadding = 8.0;
+    const rightPadding = 50.0;
+    final drawableWidth = _chartWidth - leftPadding - rightPadding;
+    final totalKlineWidth = widget.klines.length * _candleWidth;
+
+    // 如果K线总宽度不足以填满可绘制区域，自动加载更多历史
+    if (totalKlineWidth < drawableWidth) {
+      widget.onLoadMoreHistory?.call();
+    }
   }
 
   /// 滚动使最新 K 线在屏幕中心显示