feat: real-time WebSocket dashboard with live monitoring

- Dashboard: Multi-panel monitoring UI served on port 3000
  System tab: cluster overview, live event stream, pipeline latency monitor
  Trading tab: P&L summary with equity curve, L2 order book, execution table
  Debug tab: strategy inspector, state hash monitor for determinism verification
- README: Full documentation with architecture diagrams, strategy deep-dive,
  crate structure, test coverage, screenshots from live Binance testnet session
- Screenshots: System, Trading, Debug dashboard views

Author: conditional-team