docs: Document ADX-based adaptive runner SL system

Updated copilot-instructions.md with Nov 19, 2025 enhancement:

Architecture Overview - Exit Strategy:
- Added runner SL section with ADX-based positioning
- Documented three-tier system: <20 (0%), 20-25 (-0.3%), >25 (-0.55%)
- Explained rationale: Entry at candle close = natural pullbacks
- Risk management: Only accept drawdown on strong trends
- Example outcomes: ADX 18 → +$38.70, ADX 29 → +$22.20 worst case

Position Manager Section:
- Replaced "Dynamic SL adjustments: breakeven" with ADX-based logic
- Implementation details: Checks trade.adxAtEntry in TP1 handler
- Logging format: "🔒 ADX-based runner SL: 29.3 → -0.55%"
- Data collection phase: 50-100 trades for threshold optimization
- Noted TP1 default is 60% (not 75% - old value)

Key points documented:
- Adaptive vs fixed approach (capital preservation on weak trends)
- Integration with ADX trailing stop multiplier (both trend-adaptive)
- Natural retracement tolerance (entry at top requires -1% room)
- Future optimization plan (adjust 20/25 thresholds based on data)

Related commits:
- 66b2922: Implementation
- 7cf00cf: Fixed runner SL to -0.55% (replaced by ADX-based)
- d09838d: ADX trailing stop multiplier

.github/copilot-instructions.md

@@ -50,6 +50,13 @@
   - Safety bounds: MIN/MAX caps prevent extremes
   - Falls back to fixed % if ATR unavailable
 - **Runner:** 40% remaining after TP1 (configurable via `TAKE_PROFIT_1_SIZE_PERCENT=60`)
+- **Runner SL after TP1:** ADX-based adaptive positioning (Nov 19, 2025):
+  - ADX < 20: SL at 0% (breakeven) - Weak trend, preserve TP1 profit
+  - ADX 20-25: SL at -0.3% - Moderate trend, some retracement room
+  - ADX > 25: SL at -0.55% - Strong trend, full retracement tolerance
+  - **Rationale:** Entry at candle close = always at top, natural -1% to -1.5% pullbacks common
+  - **Risk management:** Only accept runner drawdown on high-probability strong trends
+  - Worst case examples: ADX 18 → +$38.70 total, ADX 29 → +$22.20 if runner stops (but likely catches big move)
 - **Trailing Stop:** ATR-based with ADX multiplier (Nov 19, 2025 enhancement):
   - Base: ATR × 1.5 multiplier
   - **ADX-based widening (graduated):**
@@ -498,9 +505,16 @@ await positionManager.addTrade(activeTrade)
 
 **Key behaviors:**
 - Tracks `ActiveTrade` objects in a Map
-- **TP2-as-Runner system**: TP1 (configurable %, default 75%) → TP2 trigger (no close, activate trailing) → Runner (remaining %) with ATR-based trailing stop
-- Dynamic SL adjustments: Moves to breakeven after TP1, locks profit at +1.2%
-- **On-chain order synchronization:** After TP1 hits, calls `cancelAllOrders()` then `placeExitOrders()` with updated SL price at breakeven (uses `retryWithBackoff()` for rate limit handling)
+- **TP2-as-Runner system**: TP1 (configurable %, default 60%) → TP2 trigger (no close, activate trailing) → Runner (remaining 40%) with ATR-based trailing stop
+- **ADX-based runner SL after TP1 (Nov 19, 2025):** Adaptive positioning based on trend strength
+  - ADX < 20: SL at 0% (breakeven) - Weak trend, preserve capital
+  - ADX 20-25: SL at -0.3% - Moderate trend, some retracement room
+  - ADX > 25: SL at -0.55% - Strong trend, full retracement tolerance
+  - **Implementation:** Checks `trade.adxAtEntry` in TP1 handler, calculates SL dynamically
+  - **Logging:** Shows ADX and selected SL: `🔒 ADX-based runner SL: 29.3 → -0.55%`
+  - **Rationale:** Entry at candle close = top of candle, -1% to -1.5% pullbacks are normal
+  - **Data collection:** After 50-100 trades, will optimize ADX thresholds (20/25) based on stop-out rates
+- **On-chain order synchronization:** After TP1 hits, calls `cancelAllOrders()` then `placeExitOrders()` with updated SL price (uses `retryWithBackoff()` for rate limit handling)
 - **ATR-based trailing stop with ADX multiplier (Nov 19, 2025):** 
   - Base calculation: `(atrAtEntry / currentPrice × 100) × trailingStopAtrMultiplier`
   - **ADX-based widening:** Multiplier adjusted based on trend strength at entry