Add comprehensive stop loss and take profit functionality

- Added stop loss and take profit parameters to TradeParams interface
- Implemented conditional order placement in executeTrade method
- Added ZERO import and closePosition method to DriftTradingService
- Enhanced trade API to handle stop loss/take profit parameters
- Added position fetching and closing functionality to AdvancedTradingPanel
- Added open positions display with close buttons
- Implemented risk management calculations and UI
- Added conditional order tracking in TradeResult interface

app/api/drift/close-position/route.ts

@@ -0,0 +1,46 @@
+import { NextResponse } from 'next/server'
+import { driftTradingService } from '../../../../lib/drift-trading'
+
+export async function POST(request: Request) {
+  try {
+    const { symbol, amount } = await request.json()
+    
+    console.log(`🔒 Close position request: ${amount || 'ALL'} ${symbol}`)
+    
+    // Validate inputs
+    if (!symbol) {
+      return NextResponse.json(
+        { success: false, error: 'Symbol is required' },
+        { status: 400 }
+      )
+    }
+
+    // Execute position close
+    const result = await driftTradingService.closePosition(symbol, amount)
+    
+    if (result.success) {
+      console.log(`✅ Position closed successfully: ${result.txId}`)
+      return NextResponse.json({
+        success: true,
+        txId: result.txId,
+        message: `Position in ${symbol} closed successfully`
+      })
+    } else {
+      console.error(`❌ Failed to close position: ${result.error}`)
+      return NextResponse.json(
+        { success: false, error: result.error },
+        { status: 500 }
+      )
+    }
+    
+  } catch (error: any) {
+    console.error('❌ Close position API error:', error)
+    return NextResponse.json(
+      { 
+        success: false, 
+        error: error.message || 'Failed to close position'
+      }, 
+      { status: 500 }
+    )
+  }
+}