feat(web): M9-3 K线 Chart 组件（candlestick + 量 + MA + Signal↔Fill 标记）

- components/StockChart/CandleChart.tsx：ECharts candlestick（红涨绿跌）+ 成交量副网格 +
  MA20/MA60 叠加 + 事件标记：成交 fills 实心三角、未成交信号空心三角（v3 §20.3）；
  组件只展示不计算；层隔离便于替换 TradingView Lightweight Charts
- lib/types.ts：ChartResult/OHLC/Volume/Series/Marker DTO
- tsc --noEmit 通过

frontend/web/lib/types.ts

@@ -186,3 +186,43 @@ export interface SignalRun {
   signal_id: string;
   result: SignalResult;
 }
+
+/* ---- Chart Service（v3 §20，与 domain/entities/chart.py 对应） ---- */
+
+export interface ChartOHLC {
+  time: string;
+  open?: number | null;
+  high?: number | null;
+  low?: number | null;
+  close?: number | null;
+}
+export interface ChartVolumePoint { time: string; value?: number | null }
+export interface ChartSeriesPoint { time: string; value?: number | null }
+export interface ChartMarker {
+  time: string;
+  kind: string; // selection | signal_buy|signal_sell|signal_watch | fill_buy|fill_sell
+  symbol?: string;
+  price?: number | null;
+  score?: number | null;
+  text: string[];
+  ref_id?: string | null;
+}
+export interface ChartResult {
+  metadata: {
+    symbol: string;
+    name?: string;
+    adjust_mode: string;
+    execution_price_basis?: string | null;
+    start?: string | null;
+    end?: string | null;
+    bar_count: number;
+    indicator_windows: number[];
+  };
+  bars: ChartOHLC[];
+  volume: ChartVolumePoint[];
+  indicators: Record<string, ChartSeriesPoint[]>;
+  selections: ChartMarker[];
+  signals: ChartMarker[];
+  fills: ChartMarker[];
+  factor_values?: Record<string, ChartSeriesPoint[]>;
+}