critical: Fix ghost detection P&L compounding - delete from Map BEFORE check

Bug: Multiple monitoring loops detect ghost simultaneously
- Loop 1: has(tradeId) → true → proceeds
- Loop 2: has(tradeId) → true → ALSO proceeds (race condition)
- Both send Telegram notifications with compounding P&L

Real incident (Dec 2, 2025):
- Manual SHORT at $138.84
- 23 duplicate notifications
- P&L compounded: -$47.96 → -$1,129.24 (23× accumulation)
- Database shows single trade with final compounded value

Fix: Map.delete() returns true if key existed, false if already removed
- Call delete() FIRST
- Check return value
 proceeds
- All other loops get false → skip immediately
- Atomic operation prevents race condition

Pattern: This is variant of Common Pitfalls #48, #49, #59, #60, #61
- All had "check then delete" pattern
- All vulnerable to async timing issues
- Solution: "delete then check" pattern
- Map.delete() is synchronous and atomic

Files changed:
- lib/trading/position-manager.ts lines 390-410

Related: DUPLICATE PREVENTED message was working but too late

app/api/analytics/process-historical/route.ts

@@ -0,0 +1,54 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { getBlockedSignalTracker } from '@/lib/analysis/blocked-signal-tracker'
+
+/**
+ * ONE-TIME BATCH PROCESSING ENDPOINT
+ * 
+ * Purpose: Process all BlockedSignals that have completed their tracking window
+ * using historical MarketData for minute-precision timing analysis.
+ * 
+ * This endpoint:
+ * 1. Finds signals NOT yet analyzed (analysisComplete = false)
+ * 2. Verifies enough historical MarketData exists
+ * 3. Analyzes minute-by-minute price movements
+ * 4. Records EXACT timing when TP1/TP2/SL hit
+ * 5. Updates database with findings
+ * 
+ * Usage: curl http://localhost:3001/api/analytics/process-historical
+ */
+export async function POST(request: NextRequest) {
+  try {
+    console.log('🔄 API: Starting batch processing of historical data...')
+    
+    const tracker = getBlockedSignalTracker()
+    
+    // This will process all signals with enough historical data
+    await tracker.processCompletedSignals()
+    
+    console.log('✅ API: Batch processing complete')
+    
+    return NextResponse.json({
+      success: true,
+      message: 'Batch processing complete - check logs for details'
+    })
+  } catch (error: any) {
+    console.error('❌ API: Error in batch processing:', error)
+    return NextResponse.json({
+      success: false,
+      error: error.message,
+      stack: error.stack
+    }, { status: 500 })
+  }
+}
+
+/**
+ * GET endpoint to check status
+ */
+export async function GET() {
+  return NextResponse.json({
+    endpoint: '/api/analytics/process-historical',
+    description: 'Batch process BlockedSignals using historical MarketData',
+    method: 'POST',
+    purpose: 'Minute-precision TP/SL timing analysis'
+  })
+}