feat(web-dashboard): React + TypeScript frontend scaffold with routing

Vite + React 18 + TypeScript project with:
- Tailwind CSS for styling (dark theme, trading-focused color palette)
- React Router with 6 dashboard routes (Trading, Risk, ML, Performance,
  Backtest, Config) and keyboard shortcuts (T/R/M/P/B/C)
- TanStack Query for data fetching with auto-refetch
- Shared lib layer: typed API client, WebSocket manager with auto-reconnect
  and topic subscriptions, auth (JWT in localStorage)
- React hooks: useAuth, useApi (query/mutation wrappers), useWebSocket
- DashboardLayout with nav tabs and StatusBar (WS connection, auth status)
- Stub pages with placeholder component layouts matching design doc

Vite proxy configured to forward /api/* to gateway at localhost:3000.
TypeScript passes with zero errors, production build succeeds.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web-dashboard/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?