Fix P&L calculation and signal flip detection

- Fix external closure P&L using tp1Hit flag instead of currentSize
- Add direction change detection to prevent false TP1 on signal flips
- Signal flips now recorded with accurate P&L as 'manual' exits
- Add retry logic with exponential backoff for Solana RPC rate limits
- Create /api/trading/cancel-orders endpoint for manual cleanup
- Improves data integrity for win/loss statistics

lib/drift/orders.ts

@@ -624,6 +624,33 @@ export async function closePosition(
 /**
  * Cancel all open orders for a specific market
  */
+/**
+ * Retry a function with exponential backoff for rate limit errors
+ */
+async function retryWithBackoff<T>(
+  fn: () => Promise<T>,
+  maxRetries: number = 3,
+  baseDelay: number = 2000
+): Promise<T> {
+  for (let attempt = 0; attempt <= maxRetries; attempt++) {
+    try {
+      return await fn()
+    } catch (error) {
+      const errorMessage = error instanceof Error ? error.message : String(error)
+      const isRateLimit = errorMessage.includes('429') || errorMessage.includes('rate limit')
+      
+      if (!isRateLimit || attempt === maxRetries) {
+        throw error
+      }
+      
+      const delay = baseDelay * Math.pow(2, attempt)
+      console.log(`⏳ Rate limited, retrying in ${delay / 1000}s... (attempt ${attempt + 1}/${maxRetries})`)
+      await new Promise(resolve => setTimeout(resolve, delay))
+    }
+  }
+  throw new Error('Max retries reached')
+}
+
 export async function cancelAllOrders(
   symbol: string
 ): Promise<{ success: boolean; cancelledCount?: number; error?: string }> {
@@ -667,12 +694,14 @@ export async function cancelAllOrders(
 
     console.log(`📋 Found ${ordersToCancel.length} open orders to cancel (including trigger orders)`)
     
-    // Cancel all orders for this market (cancels all types: LIMIT, TRIGGER_MARKET, TRIGGER_LIMIT)
-    const txSig = await driftClient.cancelOrders(
-      undefined, // Cancel by market type
-      marketConfig.driftMarketIndex,
-      undefined // No specific direction filter
-    )
+    // Cancel all orders with retry logic for rate limits
+    const txSig = await retryWithBackoff(async () => {
+      return await driftClient.cancelOrders(
+        undefined, // Cancel by market type
+        marketConfig.driftMarketIndex,
+        undefined // No specific direction filter
+      )
+    })
     
     console.log(`✅ Orders cancelled! Transaction: ${txSig}`)