docs: Update Common Pitfall #56 with order filtering bug fix

Added Nov 21 false positive investigation and resolution:
- Bot showed '32 open orders' when Drift UI showed 0
- Root cause: orderId > 0 check didn't verify baseAssetAmount
- Drift's 32-slot array contained historical metadata
- Fix: Enhanced filter with baseAssetAmount.eq(new BN(0)) check
- Result: Accurate order count reporting

Updated with correct filtering code example and dual commit references.

.github/copilot-instructions.md

@@ -2970,15 +2970,22 @@ trade.realizedPnL += actualRealizedPnL  // NOT: result.realizedPnL from SDK
     - **Impact:** Multi-timeframe data collection now operational for Phase 1 analysis (50+ signals per timeframe target)
     - **Lesson:** Background jobs should use Drift oracle prices (always available) not Pyth cache (real-time only). Always initialize external services before calling their methods. Verify background jobs are actually working by checking database state, not just logs.
 
-56. **Ghost orders after external closures (CRITICAL - Fixed Nov 20, 2025):**
+56. **Ghost orders after external closures (CRITICAL - Fixed Nov 20, 2025) + False order count bug (Fixed Nov 21, 2025):**
     - **Symptom:** Position closed externally (on-chain SL/TP order filled), but TP/SL orders remain active on Drift
     - **Root Cause:** Position Manager's external closure handler didn't call `cancelAllOrders()` before completing trade
     - **Real incident (Nov 20, 13:30 CET):**
       * SHORT position stopped out at $142.48
       * Position closed successfully on Drift
-      * TP1 order at $140.66 still active (32 total ghost orders found!)
-      * Manual cleanup via `/api/trading/cancel-orders` cancelled 32 orders
+      * TP1 order at $140.66 still active
+      * Manual cleanup via `/api/trading/cancel-orders` cancelled orders
       * Risk: If price dropped to $140.66 later, ghost order would fill → unintended LONG position
+    - **FALSE POSITIVE BUG (Nov 21, 2025):**
+      * Bot logs showed "32 open orders to cancel" on every restart
+      * Drift UI showed 0 orders (correct)
+      * Root cause: Filter checked `orderId > 0` but didn't verify `baseAssetAmount`
+      * Drift's 32-slot order array contained historical metadata with non-zero orderIds but zero baseAssetAmount
+      * Fix: Added `baseAssetAmount.eq(new BN(0))` check to filter truly active orders
+      * Result: Bot now correctly reports 0 orders when none exist
     - **Impact:** Every external closure (SL/TP fills) leaves ghost orders on exchange
     - **Why dangerous:**
       * Ghost orders can trigger unintended positions if price moves to those levels
@@ -3023,11 +3030,24 @@ trade.realizedPnL += actualRealizedPnL  // NOT: result.realizedPnL from SDK
       * Update database with exit details
       * Stop monitoring if no more trades
       * Clean slate - no ghost orders left
-    - **Why 32 orders:** Drift SDK's `userAccount.orders` array has 32 order slots, bot found SOL-PERP orders in many slots from current + previous trades
-    - **Files changed:** `lib/trading/position-manager.ts` - Added order cancellation to external closure handler
-    - **Commit:** a3a6222 "critical: Cancel ghost orders after external closures"
-    - **Deployed:** Nov 20, 2025 15:25 CET
-    - **Lesson:** When detecting external closures, always clean up ALL related on-chain state (orders, positions). Ghost orders are financial risks - they can execute when you're not watching.
+    - **Why 32 orders:** Drift SDK's `userAccount.orders` array has 32 order slots (fixed size), old filter counted slots with non-zero orderIds even when baseAssetAmount was zero
+    - **Correct filtering (Nov 21, 2025):**
+    ```typescript
+    const ordersToCancel = userAccount.orders.filter(
+      (order: any) => {
+        if (order.marketIndex !== marketConfig.driftMarketIndex) return false
+        if (!order.orderId || order.orderId === 0) return false
+        // CRITICAL: Check baseAssetAmount - empty slots have zero amount
+        if (!order.baseAssetAmount || order.baseAssetAmount.eq(new BN(0))) return false
+        return true
+      }
+    )
+    console.log(`📋 Found ${ordersToCancel.length} open orders (checked ${userAccount.orders.length} total slots)`)
+    ```
+    - **Files changed:** `lib/drift/orders.ts` (cancelAllOrders function), `lib/trading/position-manager.ts` (external closure handler)
+    - **Commits:** a3a6222 "critical: Cancel ghost orders after external closures" (Nov 20), 29fce01 "fix: Correct order filtering" (Nov 21)
+    - **Deployed:** Nov 20, 2025 15:25 CET (ghost cleanup), Nov 21, 2025 (accurate filtering)
+    - **Lesson:** When detecting external closures, always clean up ALL related on-chain state (orders, positions). Ghost orders are financial risks - they can execute when you're not watching. Always verify SDK filter logic matches reality - check transaction results, not just logs.
 
 57. **P&L calculation inaccuracy for external closures (CRITICAL - Fixed Nov 20, 2025):**
     - **Symptom:** Database P&L shows -$101.68 when Drift UI shows -$138.35 actual (36% error)