fix: full arb table + net profit columns in price view

- ArbTable: removed slice(0,10) cap, shows all 42 opps (21x2)
- PriceTable: added net_bg_to_hl and net_hl_to_bg columns
- Backend SSE: sends net profit for both directions per coin

dashboard.go

@@ -356,6 +356,18 @@ func (d *Dashboard) broadcastLoop() {
 				spreadPct := (hlP - bgP) / bgP * 100
 				entry["bg_hl_spread"] = spreadPct
 				d.spreads.Record(coin.Name, spreadPct)
+
+				// Both directions net profit after fees (4 taker fees: 2 entry + 2 exit)
+				cost := bgP * (1 + takerFees[ExBitget]/100)
+				revenue := hlP * (1 - takerFees[ExHyperLiquid]/100)
+				netBG := (revenue/cost-1)*100 - 2*(takerFees[ExBitget]+takerFees[ExHyperLiquid])
+
+				cost = hlP * (1 + takerFees[ExHyperLiquid]/100)
+				revenue = bgP * (1 - takerFees[ExBitget]/100)
+				netHL := (revenue/cost-1)*100 - 2*(takerFees[ExHyperLiquid]+takerFees[ExBitget])
+
+				entry["net_bg_to_hl"] = math.Round(netBG*10000) / 10000
+				entry["net_hl_to_bg"] = math.Round(netHL*10000) / 10000
 			}
 
 			prices = append(prices, entry)