feat: ATR-based trailing stop + rate limit monitoring

MAJOR FIXES:
- ATR-based trailing stop for runners (was fixed 0.3%, now adapts to volatility)
- Fixes runners with +7-9% MFE exiting for losses
- Typical improvement: 2.24x more room (0.3% → 0.67% at 0.45% ATR)
- Enhanced rate limit logging with database tracking
- New /api/analytics/rate-limits endpoint for monitoring

DETAILS:
- Position Manager: Calculate trailing as (atrAtEntry / price × 100) × multiplier
- Config: TRAILING_STOP_ATR_MULTIPLIER=1.5, MIN=0.25%, MAX=0.9%
- Settings UI: Added ATR multiplier controls
- Rate limits: Log hits/recoveries/exhaustions to SystemEvent table
- Documentation: ATR_TRAILING_STOP_FIX.md + RATE_LIMIT_MONITORING.md

IMPACT:
- Runners can now capture big moves (like morning's $172→$162 SOL drop)
- Rate limit visibility prevents silent failures
- Data-driven optimization for RPC endpoint health

lib/trading/position-manager.ts

@@ -21,6 +21,7 @@ export interface ActiveTrade {
   entryTime: number
   positionSize: number
   leverage: number
+  atrAtEntry?: number // ATR value at entry for ATR-based trailing stop
   
   // Targets
   stopLossPrice: number
@@ -761,6 +762,22 @@ export class PositionManager {
       // Calculate how much to close based on TP2 size percent
       const percentToClose = this.config.takeProfit2SizePercent
       
+      // CRITICAL FIX: If percentToClose is 0, don't call executeExit (would close 100% due to minOrderSize)
+      // Instead, just mark TP2 as hit and activate trailing stop on full remaining position
+      if (percentToClose === 0) {
+        trade.tp2Hit = true
+        trade.trailingStopActive = true // Activate trailing stop immediately
+        
+        console.log(`🏃 TP2-as-Runner activated: ${((trade.currentSize / trade.positionSize) * 100).toFixed(1)}% remaining with trailing stop`)
+        console.log(`📊 No position closed at TP2 - full ${trade.currentSize.toFixed(2)} USD remains as runner`)
+        
+        // Save state after TP2
+        await this.saveTradeState(trade)
+        
+        return
+      }
+      
+      // If percentToClose > 0, execute partial close
       await this.executeExit(trade, percentToClose, 'TP2', currentPrice)
       
       // If some position remains, mark TP2 as hit and activate trailing stop
@@ -787,9 +804,34 @@ export class PositionManager {
       
       // If trailing stop is active, adjust SL dynamically
       if (trade.trailingStopActive) {
+        // Calculate ATR-based trailing distance
+        let trailingDistancePercent: number
+        
+        if (trade.atrAtEntry && trade.atrAtEntry > 0) {
+          // ATR-based: Use ATR% * multiplier
+          const atrPercent = (trade.atrAtEntry / currentPrice) * 100
+          const rawDistance = atrPercent * this.config.trailingStopAtrMultiplier
+          
+          // Clamp between min and max
+          trailingDistancePercent = Math.max(
+            this.config.trailingStopMinPercent,
+            Math.min(this.config.trailingStopMaxPercent, rawDistance)
+          )
+          
+          console.log(`📊 ATR-based trailing: ${trade.atrAtEntry.toFixed(4)} (${atrPercent.toFixed(2)}%) × ${this.config.trailingStopAtrMultiplier}x = ${trailingDistancePercent.toFixed(2)}%`)
+        } else {
+          // Fallback to configured legacy percent with min/max clamping
+          trailingDistancePercent = Math.max(
+            this.config.trailingStopMinPercent,
+            Math.min(this.config.trailingStopMaxPercent, this.config.trailingStopPercent)
+          )
+          
+          console.log(`⚠️ No ATR data, using fallback: ${trailingDistancePercent.toFixed(2)}%`)
+        }
+        
         const trailingStopPrice = this.calculatePrice(
           trade.peakPrice,
-          -this.config.trailingStopPercent, // Trail below peak
+          -trailingDistancePercent, // Trail below peak
           trade.direction
         )
         
@@ -802,7 +844,7 @@ export class PositionManager {
           const oldSL = trade.stopLossPrice
           trade.stopLossPrice = trailingStopPrice
           
-          console.log(`📈 Trailing SL updated: ${oldSL.toFixed(4)} → ${trailingStopPrice.toFixed(4)} (${this.config.trailingStopPercent}% below peak $${trade.peakPrice.toFixed(4)})`)
+          console.log(`📈 Trailing SL updated: ${oldSL.toFixed(4)} → ${trailingStopPrice.toFixed(4)} (${trailingDistancePercent.toFixed(2)}% below peak $${trade.peakPrice.toFixed(4)})`)
           
           // Save state after trailing SL update (every 10 updates to avoid spam)
           if (trade.priceCheckCount % 10 === 0) {