Proper log rotation, filename compatibility with windows

pkg/logutil/factory.go

@@ -54,11 +54,13 @@ func NewLogger(logPath string) *Logger {
 	consoleEncoderCore := zapcore.NewCore(consoleEncoder, zapcore.AddSync(os.Stdout), zapLevel)
 
 	// Set up file logging with overwrite mode
-	logFile := zapcore.AddSync(&lumberjack.Logger{
+	lj := lumberjack.Logger{
 		Filename:   logPath,
 		MaxSize:    10, // megabytes
 		MaxBackups: 20,
-	})
+	}
+	lj.Rotate()
+	logFile := zapcore.AddSync(&lj)
 	fmt.Println("Logging to", logPath)
 
 	fileCfg := zapcore.EncoderConfig{