feat(v9): Complete MA gap backend integration

Integrated MA gap analysis into signal quality evaluation pipeline:

BACKEND SCORING (lib/trading/signal-quality.ts):
- Added maGap?: number parameter to scoreSignalQuality interface
- Implemented convergence/divergence scoring logic:
  * LONG: +15pts tight bullish (0-2%), +12pts converging (-2-0%), +8pts early momentum (-5--2%)
  * SHORT: +15pts tight bearish (-2-0%), +12pts converging (0-2%), +8pts early momentum (2-5%)
  * Penalties: -5pts for misaligned MA structure (>5% wrong direction)

N8N PARSER (workflows/trading/parse_signal_enhanced.json):
- Added MAGAP:([-\d.]+) regex pattern for negative number support
- Extracts maGap from TradingView v9 alert messages
- Returns maGap in parsed output (backward compatible with v8)
- Updated comment to show v9 format

API ENDPOINTS:
- app/api/trading/check-risk/route.ts: Pass maGap to scoreSignalQuality (2 calls)
- app/api/trading/execute/route.ts: Pass maGap to scoreSignalQuality (2 calls)

FULL PIPELINE NOW COMPLETE:
1. TradingView v9 → Generates signal with MAGAP field
2. n8n webhook → Extracts maGap from alert message
3. Backend scoring → Evaluates MA gap convergence (+8 to +15 pts)
4. Quality threshold → Borderline signals (75-85) can reach 91+
5. Execute decision → Only signals scoring ≥91 are executed

MOTIVATION:
Helps borderline quality signals reach execution threshold without overriding
safety rules. Addresses Nov 25 missed opportunity where good signal had MA
convergence but borderline quality score.

TESTING REQUIRED:
- Verify n8n parses MAGAP correctly from v9 alerts
- Confirm backend receives maGap parameter
- Validate MA gap scoring applied to quality calculation
- Monitor first 10-20 v9 signals for scoring accuracy

app/api/trading/check-risk/route.ts

@@ -94,6 +94,7 @@ async function shouldAllowScaling(
     rsi: newSignal.rsi || 50,
     volumeRatio: newSignal.volumeRatio || 1,
     pricePosition: newSignal.pricePosition,
+    maGap: newSignal.maGap, // V9: MA gap convergence scoring
     direction: newSignal.direction,
     symbol: newSignal.symbol,
     currentPrice: newSignal.currentPrice,
@@ -373,6 +374,7 @@ export async function POST(request: NextRequest): Promise<NextResponse<RiskCheck
         rsi: body.rsi || 0,
         volumeRatio: body.volumeRatio || 0,
         pricePosition: body.pricePosition || 0,
+        maGap: body.maGap, // V9: MA gap convergence scoring
         direction: body.direction,
         symbol: body.symbol,
         currentPrice: currentPrice,