feat: Hybrid RPC fallback system (Alchemy → Helius)

- Automatic fallback after 2 consecutive rate limits
- Primary: Alchemy (300M CU/month, stable for normal ops)
- Fallback: Helius (10 req/sec, backup for startup bursts)
- Reduced startup validation: 6h window, 5 trades (was 24h, 20 trades)
- Multi-position safety check (prevents order cancellation conflicts)
- Rate limit-aware retry logic with exponential backoff

Implementation:
- lib/drift/client.ts: Added fallbackConnection, switchToFallbackRpc()
- .env: SOLANA_FALLBACK_RPC_URL configuration
- lib/startup/init-position-manager.ts: Reduced validation scope
- lib/trading/position-manager.ts: Multi-position order protection

Tested: System switched to fallback on startup, Position Manager active
Result: 1 active trade being monitored after automatic RPC switch

scripts/place-manual-orders.mjs

@@ -0,0 +1,53 @@
+#!/usr/bin/env node
+/**
+ * Emergency script to manually place TP/SL orders for unprotected position
+ */
+
+const API_URL = 'http://localhost:3001'
+
+// Trade details from database
+const tradeId = 'cmhyw5pn7000imo07n65ihi8y'
+const symbol = 'SOL-PERP'
+const direction = 'long'
+const entryPrice = 137.069998
+const positionSizeUSD = 42.92421
+const stopLossPrice = 135.69929802
+const tp1Price = 137.618277992
+const tp2Price = 138.029487986
+
+console.log('🚨 EMERGENCY: Placing TP/SL orders manually')
+console.log(`Trade ID: ${tradeId}`)
+console.log(`Symbol: ${symbol}`)
+console.log(`Direction: ${direction}`)
+console.log(`Entry: $${entryPrice}`)
+console.log(`Size: $${positionSizeUSD}`)
+console.log(`SL: $${stopLossPrice}`)
+console.log(`TP1: $${tp1Price}`)
+console.log(`TP2: $${tp2Price}`)
+
+// Call internal API
+const response = await fetch(`${API_URL}/api/trading/execute`, {
+  method: 'POST',
+  headers: {
+    'Content-Type': 'application/json',
+  },
+  body: JSON.stringify({
+    action: 'place_exit_orders_only',
+    symbol,
+    direction,
+    entryPrice,
+    positionSizeUSD,
+    stopLossPrice,
+    tp1Price,
+    tp2Price,
+  })
+})
+
+const result = await response.json()
+console.log('\n📊 Result:', JSON.stringify(result, null, 2))
+
+if (result.success) {
+  console.log('✅ Orders placed successfully!')
+} else {
+  console.error('❌ Failed to place orders:', result.error)
+}