- Added order cancellation to Position Manager's external closure handler
- When on-chain SL/TP orders close position, remaining orders now cancelled automatically
- Prevents ghost orders from triggering unintended positions
- Real incident: Nov 20 SHORT stop-out left 32 ghost orders on Drift
- Risk: Ghost TP1 at $140.66 could fill later, creating unwanted LONG position
- Fix: Import cancelAllOrders() and call after trade removed from monitoring
- Non-blocking: Logs errors but doesn't fail trade closure if cancellation fails
- Files: lib/trading/position-manager.ts (external closure handler ~line 920)
- Documented as Common Pitfall #56
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