feat: Add automated profit withdrawal system

- UI page: /withdrawals with stats dashboard and config form
- Settings API: GET/POST for .env configuration
- Stats API: Real-time profit and withdrawal calculations
- Execute API: Safe withdrawal with Drift SDK integration
- Drift service: withdrawFromDrift() with USDC spot market (index 0)
- Safety checks: Min withdrawal amount, min account balance, profit-only
- Telegram notifications: Withdrawal alerts with Solscan links
- Dashboard navigation: Added Withdrawals card (3-card grid)

User goal: 10% of profits automatically withdrawn on schedule
Current: Manual trigger ready, scheduled automation pending
Files: 5 new (withdrawals page, 3 APIs, Drift service), 2 modified

app/api/withdrawals/stats/route.ts

@@ -0,0 +1,83 @@
+/**
+ * Withdrawal Stats API
+ * 
+ * Returns current account statistics for withdrawal calculations
+ */
+
+import { NextResponse } from 'next/server'
+import { getPrismaClient } from '@/lib/database/trades'
+import { initializeDriftService } from '@/lib/drift/client'
+
+export async function GET() {
+  try {
+    const prisma = getPrismaClient()
+    
+    // Get total invested (from roadmap: $546)
+    const totalInvested = 546
+    
+    // Get current Drift balance
+    const driftService = await initializeDriftService()
+    const health = await driftService.getAccountHealth()
+    const currentBalance = parseFloat(health.freeCollateral)
+    
+    // Calculate total P&L from database
+    const trades = await prisma.trade.findMany({
+      where: {
+        exitReason: { not: null },
+      },
+      select: {
+        realizedPnL: true,
+      },
+    })
+    
+    const totalPnL = trades.reduce((sum, trade) => sum + (trade.realizedPnL || 0), 0)
+    
+    // Get total withdrawn from .env
+    const totalWithdrawn = parseFloat(process.env.TOTAL_WITHDRAWN || '0')
+    
+    // Calculate available profit
+    const availableProfit = Math.max(0, currentBalance - totalInvested)
+    
+    // Calculate next withdrawal amount
+    const withdrawalPercent = parseFloat(process.env.WITHDRAWAL_PROFIT_PERCENT || '10')
+    const nextWithdrawalAmount = availableProfit * (withdrawalPercent / 100)
+    
+    // Calculate next withdrawal time
+    let nextWithdrawalTime: string | null = null
+    if (process.env.ENABLE_AUTO_WITHDRAWALS === 'true' && process.env.LAST_WITHDRAWAL_TIME) {
+      const lastWithdrawal = new Date(process.env.LAST_WITHDRAWAL_TIME)
+      const intervalHours = parseFloat(process.env.WITHDRAWAL_INTERVAL_HOURS || '168')
+      const nextTime = new Date(lastWithdrawal.getTime() + intervalHours * 60 * 60 * 1000)
+      nextWithdrawalTime = nextTime.toISOString()
+    } else if (process.env.ENABLE_AUTO_WITHDRAWALS === 'true') {
+      // First withdrawal - schedule from now
+      const intervalHours = parseFloat(process.env.WITHDRAWAL_INTERVAL_HOURS || '168')
+      const nextTime = new Date(Date.now() + intervalHours * 60 * 60 * 1000)
+      nextWithdrawalTime = nextTime.toISOString()
+    }
+    
+    return NextResponse.json({
+      success: true,
+      currentBalance: parseFloat(currentBalance.toFixed(2)),
+      totalInvested,
+      totalPnL: parseFloat(totalPnL.toFixed(2)),
+      totalWithdrawn,
+      availableProfit: parseFloat(availableProfit.toFixed(2)),
+      nextWithdrawalAmount: parseFloat(nextWithdrawalAmount.toFixed(2)),
+      nextWithdrawalTime,
+    })
+  } catch (error: any) {
+    console.error('Failed to load withdrawal stats:', error)
+    return NextResponse.json({
+      success: false,
+      error: error.message,
+      currentBalance: 0,
+      totalInvested: 546,
+      totalPnL: 0,
+      totalWithdrawn: 0,
+      availableProfit: 0,
+      nextWithdrawalAmount: 0,
+      nextWithdrawalTime: null,
+    })
+  }
+}