feat: implement signal frequency penalties for flip-flop detection

PHASE 1 IMPLEMENTATION:
Signal quality scoring now checks database for recent trading patterns
and applies penalties to prevent overtrading and flip-flop losses.

NEW PENALTIES:
1. Overtrading: 3+ signals in 30min → -20 points
   - Detects consolidation zones where system generates excessive signals
   - Counts both executed trades AND blocked signals

2. Flip-flop: Opposite direction in last 15min → -25 points
   - Prevents rapid long→short→long whipsaws
   - Example: SHORT at 10:00, LONG at 10:12 = blocked

3. Alternating pattern: Last 3 trades flip directions → -30 points
   - Detects choppy market conditions
   - Pattern like long→short→long = system getting chopped

DATABASE INTEGRATION:
- New function: getRecentSignals() in lib/database/trades.ts
- Queries last 30min of trades + blocked signals
- Checks last 3 executed trades for alternating pattern
- Zero performance impact (fast indexed queries)

ARCHITECTURE:
- scoreSignalQuality() now async (requires database access)
- All callers updated: check-risk, execute, reentry-check
- skipFrequencyCheck flag available for special cases
- Frequency penalties included in qualityResult breakdown

EXPECTED IMPACT:
- Eliminate overnight flip-flop losses (like SOL $141-145 chop)
- Reduce overtrading during sideways consolidation
- Better capital preservation in non-trending markets
- Should improve win rate by 5-10% by avoiding worst setups

TESTING:
- Deploy and monitor next 5 signals in choppy markets
- Check logs for frequency penalty messages
- Analyze if blocked signals would have been losers

Files changed:
- lib/database/trades.ts: Added getRecentSignals()
- lib/trading/signal-quality.ts: Made async, added frequency checks
- app/api/trading/check-risk/route.ts: await + symbol parameter
- app/api/trading/execute/route.ts: await + symbol parameter
- app/api/analytics/reentry-check/route.ts: await + skipFrequencyCheck

app/api/analytics/reentry-check/route.ts

@@ -139,13 +139,15 @@ export async function POST(request: NextRequest) {
     console.log(`📊 Recent performance: ${last3Count} trades, ${winRate.toFixed(0)}% WR, ${avgPnL.toFixed(2)}% avg P&L`)
 
     // 3. Score the re-entry with real/fallback metrics
-    const qualityResult = scoreSignalQuality({
+    const qualityResult = await scoreSignalQuality({
       atr: metrics.atr,
       adx: metrics.adx,
       rsi: metrics.rsi,
       volumeRatio: metrics.volumeRatio,
       pricePosition: metrics.pricePosition,
-      direction: direction as 'long' | 'short'
+      direction: direction as 'long' | 'short',
+      symbol: symbol,
+      skipFrequencyCheck: true, // Re-entry check already considers recent trades
     })
 
     let finalScore = qualityResult.score