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

.github/copilot-instructions.md

@@ -609,6 +609,16 @@ trade.realizedPnL += actualRealizedPnL  // NOT: result.realizedPnL from SDK
     - Applies to all aggregations: SUM(), AVG(), ROUND() - all return Decimal types
     - Example: `/api/analytics/version-comparison` converts all numeric fields
 
+20. **ATR-based trailing stop implementation (Nov 11, 2025):** Runner system was using FIXED 0.3% trailing, causing immediate stops:
+    - **Problem:** At $168 SOL, 0.3% = $0.50 wiggle room. Trades with +7-9% MFE exited for losses.
+    - **Fix:** `trailingDistancePercent = (atrAtEntry / currentPrice * 100) × trailingStopAtrMultiplier`
+    - **Config:** `TRAILING_STOP_ATR_MULTIPLIER=1.5`, `MIN=0.25%`, `MAX=0.9%`, `ACTIVATION=0.5%`
+    - **Typical improvement:** 0.45% ATR × 1.5 = 0.675% trail ($1.13 vs $0.50 = 2.26x more room)
+    - **Fallback:** If `atrAtEntry` unavailable, uses clamped legacy `trailingStopPercent`
+    - **Log verification:** Look for "📊 ATR-based trailing: 0.0045 (0.52%) × 1.5x = 0.78%" messages
+    - **ActiveTrade interface:** Must include `atrAtEntry?: number` field for calculation
+    - See `ATR_TRAILING_STOP_FIX.md` for full details and database analysis
+
 ## File Conventions
 
 - **API routes:** `app/api/[feature]/[action]/route.ts` (Next.js 15 App Router)