Add signal quality version tracking to database

- Added signalQualityVersion field to Trade model
- Tracks which scoring logic version was used for each trade
- v1: Original logic (price position < 5% threshold)
- v2: Added volume compensation for low ADX
- v3: CURRENT - Stricter logic requiring ADX > 18 for extreme positions (< 15%)

This enables future analysis to:
- Compare performance between logic versions
- Filter trades by scoring algorithm
- Data-driven improvements based on clean datasets

All new trades will be marked as v3. Old trades remain null/v1 for comparison.

app/api/trading/execute/route.ts

@@ -347,6 +347,7 @@ export async function POST(request: NextRequest): Promise<NextResponse<ExecuteTr
           volumeAtEntry: body.volumeRatio,
           pricePositionAtEntry: body.pricePosition,
           signalQualityScore: qualityResult.score,
+          signalQualityVersion: 'v3', // Stricter logic with ADX > 18 requirement
           // Phantom-specific fields
           status: 'phantom',
           isPhantom: true,
@@ -584,6 +585,7 @@ export async function POST(request: NextRequest): Promise<NextResponse<ExecuteTr
         volumeAtEntry: body.volumeRatio,
         pricePositionAtEntry: body.pricePosition,
         signalQualityScore: qualityResult.score,
+        signalQualityVersion: 'v3', // Stricter logic with ADX > 18 requirement for extreme positions
         expectedSizeUSD: requestedPositionSizeUSD,
         actualSizeUSD: actualPositionSizeUSD,
       })