Fix spot trade logic: remove incorrect positions and enhance trade history display

- Remove incorrect open positions for spot swaps (instant settlements)
- Add DELETE API route for position removal (/api/trading/positions/[positionId])
- Update existing SOL/USDC trade to clearly mark as SPOT_SWAP
- Enhance TradesHistoryPanel with visual trade type indicators:
  * SPOT_SWAP: Purple badge with ⚡ icon
  * MARKET: Blue badge with 📈 icon
  * LIMIT: Orange badge with 🎯 icon
  * STOP: Red badge with 🛑 icon
- Add trade history update functionality for modifying existing trades
- Fix container communication URLs in execute-dex route

Result: Spot trades no longer create open positions, trade history clearly shows trade types

app/api/trading/history/route.js

@@ -98,6 +98,31 @@ export async function POST(request) {
         message: `Trade added to history: ${newTrade.side} ${newTrade.amount} ${newTrade.symbol}`
       })
 
+    } else if (action === 'update') {
+      // Load existing trades
+      const tradesHistory = loadTrades()
+      const { tradeId, updates } = tradeData
+      
+      // Find and update the trade
+      const tradeIndex = tradesHistory.findIndex(trade => trade.id === tradeId)
+      
+      if (tradeIndex === -1) {
+        return NextResponse.json({
+          success: false,
+          error: 'Trade not found'
+        }, { status: 404 })
+      }
+
+      // Update the trade with new data
+      tradesHistory[tradeIndex] = { ...tradesHistory[tradeIndex], ...updates }
+      saveTrades(tradesHistory)
+
+      return NextResponse.json({
+        success: true,
+        trade: tradesHistory[tradeIndex],
+        message: `Trade updated: ${tradeId}`
+      })
+
     } else if (action === 'clear') {
       // Clear trade history
       saveTrades([])