Issue #1 (critical): reProfit false positive on price reversal
executeEntry used CalcNetProfit which auto-swaps prices when
hlP < bgP. If prices flipped between scan and execution, reProfit
reported positive even when direction was now wrong.
Fix: use netProfit() with explicit direction + verify spread
direction hasn't flipped (hlP <= bgP prevents BG->HL when
HL is no longer more expensive).
Issue #2 (medium): Scale-in was paper-only, didn't place orders
Now actually places additional orders on both legs via new
placeOrderAt(). Test mode uses mock fills. Live mode sends
real API orders. AmountUSD properly tracks total deployed
capital. Partial fill handled gracefully (don't close main leg).
Issue #3 (minor): closeLeg missing ExitTime on mock mode
P3-1: Scan optimization — only BG↔HL (50+ pair combos → 2)
P3-2: Real-time spread chart — spreadHistory ring buffer +
/api/spread-history endpoint + Chart.js spread chart
P3-3: Live position PnL — positions SSE now includes
estimated current profit/loss + current spread
P3-4: Real-time trade events — trader.OnTradeEvent callback
fires SSE 'trade_open' / 'trade_close' immediately
P3-5: Connection status monitoring — tracks last update time
per exchange, broadcast via stats.connections + /api/connections
Frontend: spread chart card, PnL column in positions,
connection status dots in stats bar,
green/red border flash on trade events
CalcNetProfit (helpers.go) has internal price-swap logic — when
price2 < price1 it swaps buy/sell sides. ScanArbWithFees relies
on netProfit being a pure strict-direction calculation (callers
try both directions via addPair). Delegation caused double-swap:
both netProfit calls in addPair returned positive profit, but
direction1's struct reported wrong exchange pair, leading to
potential loss-making trades.
Keep both formulas as independent implementations with explicit
comments warning against future merging attempts.
B#1 — sigCh shared across goroutines, SIGINT unreliable
→ context.WithCancel: main loop cancels ctx on SIGINT,
4 WS goroutines select on ctx.Done() instead of shared sigCh
B#3 — restoreOpenPositions missing LastScaleAt
→ Set LastScaleAt = tr.OpenedAt on restore so scale-in cooldown works
B#4 — dYdX heartbeat goroutine leaks on reconnect
→ Added stopHeartbeat chan + heartbeatMu mutex; close old channel
before spawning new heartbeat goroutine
B#5 — GetBitgetSize fmt.Sprintf rounds up, may exceed amountUSD
→ Added math.Floor(sz*multiplier)/multiplier before format to round
DOWN to nearest valid step size for every coin
B#6 — netProfit and CalcNetProfit duplicate formula
→ scanner.go netProfit now delegates to exchange.CalcNetProfit
B#7 — Aevo Run callback only 2 params, incompatible with startExchange
→ Changed to 4-arg callback func(coin, price, bid, ask) with bid=ask=0
B#8 — parseFloat uses fmt.Sscanf (slow, locale-sensitive)
→ Replaced with strconv.ParseFloat
B#9 — dYdX receives hlSymbols instead of its own symbol list
→ Added dydxSymbols var, built from c.HL like other exchanges