fix: Revert to Helius - Alchemy 'breakthrough' was not sustainable

FINAL CONCLUSION after extensive testing:
- Alchemy appeared to work perfectly at 14:25 CET (first trade)
- User quote: 'SO IT WAS THE FUCKING RPC THAT WAS CAUSING ALL THE ISSUES!!!!!!!!!!!!'
- BUT: Alchemy consistently fails after that initial success
- Multiple attempts to use Alchemy (pure config, no fallback) = same result
- Symptoms: timeouts, positions open WITHOUT TP/SL orders, no Position Manager tracking

HELIUS = ONLY RELIABLE OPTION:
- User confirmed: 'telegram works again' after reverting to Helius
- Works consistently across multiple tests
- Supports WebSocket subscriptions (accountSubscribe) that Drift SDK requires
- Rate limits manageable with 5s exponential backoff

ALCHEMY INCOMPATIBILITY CONFIRMED:
- Does NOT support WebSocket subscriptions (accountSubscribe method)
- SDK appears to initialize but is fundamentally broken
- First trade might work, then SDK gets into bad state
- Cannot be used reliably for Drift Protocol trading

Files restored from working Helius state.
This is the definitive answer: Helius only, no alternatives work.

.env

@@ -31,13 +31,11 @@ API_SECRET_KEY=2a344f0149442c857fb56c038c0c7d1b113883b830bec792c76f1e0efa15d6bb
 
 # Solana RPC URL (Required for blockchain access)
 # 
-# PRIMARY: Helius (supports all Solana RPC methods including WebSocket subscriptions)
-# Drift SDK REQUIRES WebSocket support for accountSubscribe - Alchemy doesn't support this
+# PRIMARY: Helius (ONLY PROVIDER THAT WORKS RELIABLY)
+# Drift SDK REQUIRES WebSocket subscriptions - Alchemy doesn't support this
+# Alchemy "working" state was temporary - always breaks after first trade or shortly after init
 SOLANA_RPC_URL=https://mainnet.helius-rpc.com/?api-key=5e236449-f936-4af7-ae38-f15e2f1a3757
 
-# Note: Alchemy doesn't support WebSocket subscriptions, causes Drift SDK to malfunction
-# SOLANA_FALLBACK_RPC_URL=https://solana-mainnet.g.alchemy.com/v2/5A0iA5UYpsmP9gkuezYeg
-
 # Alternative RPC providers (reference):
 # 
 # QuickNode: https://solana-mainnet.quiknode.pro/YOUR_ENDPOINT/