Every StartOrderSync spawned a ticker goroutine that ran forever — it
survived trader stop AND deletion, so each quick-created trader left a
permanent 30s Hyperliquid poll behind. Stacked leaks turned into an
~8s effective hammer that tripped Hyperliquid's 429 rate limit, which
then broke the symbol board, trader creation, and order sync itself.
- new trader/syncloop package: shared stoppable sync loop with
exponential failure backoff (30s base, 5min cap)
- all 9 exchanges' StartOrderSync now take the trader's stop channel
and stop when the trader stops (close broadcast from AutoTrader.Stop)
- provider/hyperliquid: GetPerpDexCoins now serves a 5min TTL cache and
falls back to the stale board when the upstream returns 429, so the
symbol panel keeps working through rate limiting
- Add server time synchronization for KuCoin API to fix timestamp error (400002)
- Return empty list instead of error when no available coins (ai500.go)
- Save cycle record even when no candidate coins (show in frontend without red error)
- Update Claude icon to Anthropic dark brand color (#141413)
- Add exchange and AI model icons to README.md and README.ja.md
- Add KuCoin order sync with proper API response parsing
- Use openFeePay/closeFeePay to determine open/close trades
- Get contract multiplier from API for accurate qty calculation
- Fix price rounding: 2 decimals -> 8 decimals for low-price coins
- Add comprehensive tests for trades, positions, and P&L
