style: format Go code with go fmt

- Fix formatting issues flagged by PR advisory checks
- Run go fmt ./... on all Go files
- No functional changes, code style improvements only

Files formatted:
- api/server.go
- auth/auth.go
- decision/engine.go
- logger/decision_logger.go
- manager/trader_manager.go
- market/monitor.go
- market/types.go
- mcp/client.go
- trader/*.go (aster, auto, binance, hyperliquid)

api/server.go

@@ -114,7 +114,6 @@ func (s *Server) setupRoutes() {
 			protected.GET("/user/signal-sources", s.handleGetUserSignalSource)
 			protected.POST("/user/signal-sources", s.handleSaveUserSignalSource)
 
-
 			// 竞赛总览
 			protected.GET("/competition", s.handleCompetition)