feat: Helius primary + Alchemy fallback for trade execution

- Helius HTTPS: Primary RPC for Drift SDK initialization and subscriptions
- Alchemy HTTPS (10K CU/s): Fallback RPC for transaction confirmations
- Added getFallbackConnection() method to DriftService
- openPosition() and closePosition() now use Alchemy for tx confirmations
- accountSubscribe errors are non-fatal warnings (SDK falls back gracefully)
- System fully operational: Drift initialized, Position Manager ready
- Trade execution will use high-throughput Alchemy for confirmations

lib/drift/client.ts

@@ -470,6 +470,13 @@ export class DriftService {
     return this.connection
   }
 
+  /**
+   * Get fallback connection (Alchemy for trade execution)
+   */
+  getFallbackConnection(): Connection | null {
+    return this.fallbackConnection || null
+  }
+
   /**
    * Get user instance
    */

lib/drift/orders.ts

@@ -146,8 +146,16 @@ export async function openPosition(
     console.log(`📝 Transaction submitted: ${txSig}`)
     
     // CRITICAL: Confirm transaction actually executed on-chain
-    console.log('⏳ Confirming transaction on-chain...')
-    const connection = driftService.getConnection()
+    // Use Alchemy (fallback RPC) for confirmation - higher throughput
+    console.log('⏳ Confirming transaction on-chain (using Alchemy for high throughput)...')
+    const alchemyConnection = driftService.getFallbackConnection()
+    const connection = alchemyConnection || driftService.getConnection()
+    
+    if (alchemyConnection) {
+      console.log('✅ Using Alchemy RPC for transaction confirmation')
+    } else {
+      console.log('⚠️ No fallback RPC available, using primary RPC')
+    }
     
     try {
       const confirmation = await connection.confirmTransaction(txSig, 'confirmed')
@@ -557,9 +565,16 @@ export async function closePosition(
     console.log(`✅ Close order placed! Transaction: ${txSig}`)
     
     // CRITICAL: Confirm transaction on-chain to prevent phantom closes
-    // BUT: Use timeout to prevent API hangs during network congestion
-    console.log('⏳ Confirming transaction on-chain (30s timeout)...')
-    const connection = driftService.getConnection()
+    // Use Alchemy (fallback RPC) for confirmation - higher throughput
+    console.log('⏳ Confirming transaction on-chain (using Alchemy, 30s timeout)...')
+    const alchemyConnection = driftService.getFallbackConnection()
+    const connection = alchemyConnection || driftService.getConnection()
+    
+    if (alchemyConnection) {
+      console.log('✅ Using Alchemy RPC for transaction confirmation')
+    } else {
+      console.log('⚠️ No fallback RPC available, using primary RPC')
+    }
     
     try {
       const confirmationPromise = connection.confirmTransaction(txSig, 'confirmed')