refactor: simplify site to match terazi minimal layout

feat: add GitHub Pages site with dark/light mode toggle

feat: add analyze command to compute stats from trade journal

feat: wire journal into executor and skip balance check in dry-run mode

feat: add trade journal with JSONL logging for paper trade analysis

feat: log reconnect attempt count in WebSocket error messages

feat: add spread/depth helpers and require minimum book depth before evaluating

feat: validate max quantity per symbol before placing orders

feat: make order book staleness and opportunity age thresholds configurable

perf: fetch initial order book snapshots in parallel batches of 10

feat: add win rate and average pnl to periodic stats output

feat: add unwind logic to sell held asset back when a mid-triangle leg fails

feat: validate min notional before placing orders

feat: reject stale opportunities in executor with 2s age guard

feat: skip stale order books in detector to avoid phantom opportunities