refactor(image): 调整水印偏移量处理逻辑

- 将 PORTRAIT 偏移量常量重命名为 PRINTER
- 根据图像旋转角度动态设置左右偏移量
- 优化旋转状态下水印位置计算逻辑

src/main/java/com/ycwl/basic/image/pipeline/stages/WatermarkStage.java

@@ -31,7 +31,7 @@ import java.util.List;
 )
 public class WatermarkStage extends AbstractPipelineStage<PhotoProcessContext> {
 
-    private static final int OFFSET_LEFT_FOR_PORTRAIT = 40;
+    private static final int OFFSET_FOR_PRINTER = 40;
 
     private final WatermarkConfig config;
 
@@ -172,7 +172,11 @@ public class WatermarkStage extends AbstractPipelineStage<PhotoProcessContext> {
 
         // 根据旋转状态自己处理 offsetLeft
         if (context.isNeedRotation()) {
-            info.setOffsetLeft(OFFSET_LEFT_FOR_PORTRAIT);
+            if (context.getImageRotation() == 90) {
+                info.setOffsetLeft(OFFSET_FOR_PRINTER);
+            } else if (context.getImageRotation() == 270) {
+                info.setOffsetRight(OFFSET_FOR_PRINTER);
+            }
         }
 
         return info;