revert: Back to last known working state (27eb5d4)

- Restored Drift client, orders, and .env from commit 27eb5d4
- Updated to current Helius API key
- ISSUE: Execute/check-risk endpoints still hang
- Root cause appears to be Drift SDK initialization hanging at runtime
- Bot initializes successfully at startup but hangs on subsequent Drift calls
- Non-Drift endpoints work fine (settings, positions query)
- Needs investigation: Drift SDK behavior or RPC interaction issue

.env

@@ -31,15 +31,15 @@ API_SECRET_KEY=2a344f0149442c857fb56c038c0c7d1b113883b830bec792c76f1e0efa15d6bb
 
 # Solana RPC URL (Required for blockchain access)
 # 
-# PRIMARY: Helius WebSocket RPC (supports accountSubscribe for Drift SDK)
+# RECOMMENDED: Helius (best performance, free tier available)
+# Get free API key at: https://helius.dev
 SOLANA_RPC_URL=https://mainnet.helius-rpc.com/?api-key=5e236449-f936-4af7-ae38-f15e2f1a3757
 
-# Fallback RPC URL (used for trade execution - higher throughput)
-# Helius: startup/subscriptions, Alchemy: trade execution
-SOLANA_FALLBACK_RPC_URL=https://solana-mainnet.g.alchemy.com/v2/5A0iA5UYpsmP9gkuezYeg
-
-# Alternative RPC providers:
+# Alternative RPC providers (if not using Helius):
+# 
 # QuickNode: https://solana-mainnet.quiknode.pro/YOUR_ENDPOINT/
+# Alchemy: https://solana-mainnet.g.alchemy.com/v2/YOUR_ALCHEMY_KEY
+# Ankr: https://rpc.ankr.com/solana
 # Public (not recommended): https://api.mainnet-beta.solana.com
 
 # ================================