Restyle the web UI as a dark trading terminal

- Single palette (web/src/styles/palette.ts) taken from the Stitch
  design, exposed as ap-* UnoCSS colors and --ap-* CSS variables and
  used for Element Plus dark theme overrides, KLineChart and the news
  iframe; zero radius, JetBrains Mono / Space Grotesk bundled locally
- New sidebar and header layout; trading page, plan card and analysis
  drawer follow the design; other pages use the same panels
- Status API reports today's closed trades, wins and net PnL, shown as
  today's PnL and win rate on the trading page

web/src/apis/trading.ts

@@ -64,7 +64,16 @@ export interface TradingStatus {
   reasoning_effort: Effort | null
   /** trader 进程离线时为空 */
   snapshot: Snapshot | null
-  today: { analyses: number, limit: number, input_tokens: number, output_tokens: number }
+  today: {
+    analyses: number
+    limit: number
+    input_tokens: number
+    output_tokens: number
+    /** 今日结束的计划笔数、其中净盈亏为正的笔数、净盈亏合计（含手续费） */
+    trades: number
+    wins: number
+    net_pnl: string
+  }
 }
 
 export interface TradingSymbol {