Omni Predictor Worker v4.0.0

This is the backend Worker for the separate Cloudflare Pages dashboard.

Endpoints: /health, /ws?symbol=BTC_USDT, /api/mexc/kline, /api/mexc/depth, /api/mexc/ticker, /api/mexc/deals, /api/mexc/contract, /api/mexc/index, /api/mexc/fair, /api/mexc/funding.

Architecture: Cloudflare Pages frontend + one Cloudflare Worker backend. No Durable Objects.