fix: Require signal quality check for position flips

**Problem:**
- Signal flips (SHORT→LONG or LONG→SHORT) were auto-approved
- Bypassed signal quality scoring, cooldown, drawdown checks
- User wanted flips ONLY if new signal has strong quality (score ≥60)

**Solution:**
- Removed early return for opposite-direction signals in check-risk
- Flips now go through FULL validation: quality score, cooldown, limits
- Execute endpoint still handles flip logic (close opposite + open new)

**New Flow:**
1. n8n sends flip signal → check-risk endpoint
2. Detects potential flip, logs 'checking quality score'
3. Continues to quality checks (not early return)
4. If score ≥60 AND all checks pass → execute handles flip
5. If score <60 → BLOCKS flip with 'Signal quality too low'

**Result:**
Flips now require signal strength, not just direction change

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

@@ -73,19 +73,16 @@ export async function POST(request: NextRequest): Promise<NextResponse<RiskCheck
         })
       }
       
-      // OPPOSITE direction - this is a signal flip/reversal (ALLOW IT)
-      console.log('🔄 Risk check: Signal flip detected', {
+      // OPPOSITE direction - potential signal flip
+      // Don't auto-allow! Let it go through normal quality checks below
+      console.log('🔄 Potential signal flip detected - checking quality score', {
         symbol: body.symbol,
         existingDirection: existingPosition.direction,
         newDirection: body.direction,
-        note: 'Will close existing and open opposite',
+        note: 'Will flip IF signal quality passes',
       })
       
-      return NextResponse.json({
-        allowed: true,
-        reason: 'Signal flip',
-        details: `Signal reversed from ${existingPosition.direction} to ${body.direction} - will flip position`,
-      })
+      // Continue to quality checks below instead of returning early
     }
     
     // 1. Check daily drawdown limit