Build an institutional trading platform with one prompt.

You are building a production-grade trading platform on the VARJIX API.

VARJIX is REST infrastructure: I bring my own Deriv App ID (operator-owned, I keep 100% of broker markup), VARJIX is the rails that handle auth, idempotency, order ledger, and per-trader scope. VARJIX never custodies trader funds — Deriv holds them.

Read the full API contract here BEFORE writing code:
- OpenAPI 3.1 spec:   https://api.varjix.com/openapi.json
- llms-full.txt:      https://api.varjix.com/llms-full.txt
- Developer console:  https://api.varjix.com/dashboard

Build me a Next.js 14 (App Router) trading platform with:
1. Trader sign-up + Deriv OAuth (using MY app ID — env DERIV_APP_ID + DERIV_OAUTH_URL)
2. After OAuth, the backend POSTs the tokens to VARJIX /v1/auth/deriv/exchange to register the trader
3. A trade page with: live tick chart (R_100), DIGITOVER/UNDER buttons, stake input, single-digit barrier picker
4. POST /v1/orders/binary on click — tick contracts settle inline; show the closed P&L immediately
5. A balance widget that polls GET /v1/balance every 5s
6. An order history table backed by GET /v1/orders (cursor-paginated)
7. Strict TypeScript, no `any`. Zod schemas for every VARJIX response. clientOrderId via crypto.randomUUID(). One `vx()` fetch helper with full error mapping (UNAUTHENTICATED, MARKET_CLOSED, INSUFFICIENT_BALANCE, INVALID_CONTRACT, BROKER_UPSTREAM, RATE_LIMITED with Retry-After).

Constraints:
- Store VARJIX_API_KEY ONLY on the server (Next.js Route Handler / Server Action). NEVER in the client.
- Every call to VARJIX must carry the Bearer key + the trader's external id.
- Use the user's stable id from your auth provider as traderExternalId (passed once on /auth/deriv/exchange, then reused).
- Idempotency: every POST /orders/binary needs a fresh UUID v4 from the SERVER (don't trust the client).

Tech defaults: Next.js 14, Tailwind, shadcn/ui, NextAuth or Clerk for trader sign-in, lightweight-charts for the chart. Dark theme. Mobile-first.

Deliverables (in this order):
1. .env.example with: VARJIX_API_KEY, VARJIX_API_BASE=https://api.varjix.com/v1, DERIV_APP_ID, DERIV_OAUTH_URL, NEXTAUTH_SECRET
2. lib/varjix.ts — typed fetch helper + Zod schemas for /v1/me, /v1/balance, /v1/orders/binary, /v1/orders, /v1/accounts
3. app/api/auth/deriv/callback/route.ts — exchange Deriv OAuth code → tokens → forward to VARJIX
4. app/api/orders/place/route.ts — server action: validates input, generates UUID, calls VARJIX, returns settled order
5. app/api/balance/route.ts — proxies GET /v1/balance for the signed-in trader
6. app/(trade)/page.tsx — UI, chart, order panel, history. Skeleton states + error toasts.
7. README with curl smoke commands for every flow.

Build this end-to-end. Show me the file tree first, then write each file.