feat(web): add Next.js portfolio with live MT5 dashboard

- Linear design system (dark canvas, lavender accent)
- Live account stats, open positions, pending orders (30s polling)
- Trade history with equity curve chart
- Backtest results table
- Proxy API routes — MT5_BASE_URL server-side only, never exposed to browser
- Deploy on Vercel: set MT5_BASE_URL env var

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

web/app/api/orders/route.ts

@@ -0,0 +1,15 @@
+import { NextResponse } from "next/server";
+import { getOrders } from "@/lib/mt5";
+import { NextRequest } from "next/server";
+
+export const dynamic = "force-dynamic";
+
+export async function GET(req: NextRequest) {
+  const symbol = req.nextUrl.searchParams.get("symbol") ?? undefined;
+  try {
+    const data = await getOrders(symbol);
+    return NextResponse.json(data);
+  } catch (e) {
+    return NextResponse.json({ error: String(e) }, { status: 502 });
+  }
+}