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.

lib/database/trades.ts

@@ -52,6 +52,7 @@ export interface CreateTradeParams {
   volumeAtEntry?: number
   pricePositionAtEntry?: number
   signalQualityScore?: number
+  signalQualityVersion?: string // Track which scoring logic version was used
   // Phantom trade fields
   status?: string
   isPhantom?: boolean