Update copilot-instructions with critical Drift SDK insights

- Document Drift SDK position.size returns USD, not token quantity
- Add Solana RPC rate limiting retry pattern with exponential backoff
- Document /api/trading/cancel-orders endpoint for ghost order cleanup
- Clarify symbol normalization requirement for manual close endpoint
- Captures lessons learned from TP1 detection and P&L calculation debugging

.github/copilot-instructions.md

@@ -136,6 +136,7 @@ const health = await driftService.getAccountHealth()
 - `openPosition()` - Opens market position with transaction confirmation
 - `closePosition()` - Closes position with transaction confirmation
 - `placeExitOrders()` - Places TP/SL orders on-chain
+- `cancelAllOrders()` - Cancels all reduce-only orders for a market
 
 **CRITICAL: Transaction Confirmation Pattern**
 Both `openPosition()` and `closePosition()` MUST confirm transactions on-chain:
@@ -152,6 +153,46 @@ console.log('✅ Transaction confirmed on-chain')
 ```
 Without this, the SDK returns signatures for transactions that never execute, causing phantom trades/closes.
 
+**CRITICAL: Drift SDK position.size is USD, not tokens**
+The Drift SDK returns `position.size` as USD notional value, NOT token quantity:
+```typescript
+// WRONG: Multiply by price (inflates by 156x for SOL at $157)
+const positionSizeUSD = position.size * currentPrice
+
+// CORRECT: Use directly as USD value
+const positionSizeUSD = Math.abs(position.size)
+```
+This affects Position Manager's TP1 detection - if calculated incorrectly, TP1 will never trigger because expected size won't match actual size.
+
+**Solana RPC Rate Limiting with Exponential Backoff**
+Solana RPC endpoints return 429 errors under load. Always use retry logic for order operations:
+```typescript
+export async function retryWithBackoff<T>(
+  operation: () => Promise<T>,
+  maxRetries: number = 3,
+  initialDelay: number = 2000
+): Promise<T> {
+  for (let attempt = 0; attempt < maxRetries; attempt++) {
+    try {
+      return await operation()
+    } catch (error: any) {
+      if (error?.message?.includes('429') && attempt < maxRetries - 1) {
+        const delay = initialDelay * Math.pow(2, attempt)
+        console.log(`⏳ Rate limited, retrying in ${delay/1000}s... (attempt ${attempt + 1}/${maxRetries})`)
+        await new Promise(resolve => setTimeout(resolve, delay))
+        continue
+      }
+      throw error
+    }
+  }
+  throw new Error('Max retries exceeded')
+}
+
+// Usage in cancelAllOrders
+await retryWithBackoff(() => driftClient.cancelOrders(...))
+```
+Without this, order cancellations fail silently during TP1→breakeven order updates, leaving ghost orders that cause incorrect fills.
+
 **Dual Stop System** (USE_DUAL_STOPS=true):
 ```typescript
 // Soft stop: TRIGGER_LIMIT at -1.5% (avoids wicks)
@@ -233,7 +274,8 @@ const driftSymbol = normalizeTradingViewSymbol(body.symbol)
 - `/api/trading/execute` - Main entry point from n8n (production, requires auth), **auto-caches market data**
 - `/api/trading/check-risk` - Pre-execution validation (duplicate check, quality score, **per-symbol cooldown**, rate limits, **symbol enabled check**)
 - `/api/trading/test` - Test trades from settings UI (no auth required, **respects symbol enable/disable**)
-- `/api/trading/close` - Manual position closing
+- `/api/trading/close` - Manual position closing (requires symbol normalization)
+- `/api/trading/cancel-orders` - **Manual order cleanup** (for stuck/ghost orders after rate limit failures)
 - `/api/trading/positions` - Query open positions from Drift
 - `/api/trading/market-data` - Webhook for TradingView market data updates (GET for debug, POST for data)
 - `/api/settings` - Get/update config (writes to .env file, **includes per-symbol settings**)