1. GetHLSize: add minimum size checks (prevent size=0 when price > amount)
2. executeEntry: orphan position warning when leg1 close also fails after leg2
3. checkExit: keep position as close_failed on failure, retryClose on each Tick
4. persistTrade: sync instead of goroutine (prevent data loss on exit)
- 🔴 Data race: Add GetPositionsCopy() returning deep copies (no shared
ArbPosition pointers). Use it in dashboard broadcastLoop + handleStatus.
- 🟡 Scale-in PnL: Track LongEntryPrices/ShortEntryPrices on ArbPosition,
compute weighted average (harmonic mean) at exit for accurate PnL.
- 🟢 CalcNetProfit: Delete dead code from exchange/helpers.go.
- 🟢 HL nonce: Add sync.Mutex around lastNonce++ (thread safety).
- 🟢 Hourly check: Change from 5-second window to minute window.
- 🟢 ExitPrice: Test mode closeLeg already handled by checkExit.