feat: safe mode — auto-protect positions when AI fails 3+ times

- Track consecutive AI failures
- After 3 failures: activate safe mode (no new positions, close/hold only)
- Auto-deactivate when AI recovers
- Keep loop running in safe mode (retry each cycle)
- Log clearly: 🛡️ SAFE MODE ACTIVATED/DEACTIVATED

trader/auto_trader.go

@@ -148,6 +148,9 @@ type AutoTrader struct {
 	userID                string             // User ID
 	gridState             *GridState         // Grid trading state (only used when StrategyType == "grid_trading")
 	claw402WalletAddr     string             // Claw402 wallet address (derived from private key at start)
+	consecutiveAIFailures int               // Consecutive AI call failures
+	safeMode              bool              // Safe mode: no new positions, protect existing ones
+	safeModeReason        string            // Why safe mode was activated
 }
 
 // NewAutoTrader creates an automatic trader