refactor(sdk): 将HGScannerLib声明为final静态变量

- 修改scannerLib字段为final类型以增强不可变性
- 保持静态初始化块不变
- 确保库加载路径配置一致

src/main/java/vip/jcfd/sdk/HGScannerWrapper.java

@@ -22,7 +22,7 @@ public class HGScannerWrapper {
     private static final Logger log = Logger.getLogger(HGScannerWrapper.class.getName());
 
     private static final int STRING_BUFFER_SIZE = 256;
-    private static HGScannerLib scannerLib;
+    private static final HGScannerLib scannerLib;
 
     static {
         NativeLibrary.addSearchPath("HGScannerLib", "C:/Program Files (x86)/HuaGoScannerLib/bin/x64");