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/package.json

@@ -10,6 +10,8 @@
   },
   "dependencies": {
     "@element-plus/icons-vue": "^2.3.2",
+    "@fontsource-variable/jetbrains-mono": "^5.3.0",
+    "@fontsource-variable/space-grotesk": "^5.3.0",
     "axios": "^1.20.0",
     "dayjs": "^1.11.23",
     "element-plus": "^2.14.7",