feat(infographic): upload PNG instead of SVG for better compatibility

- Convert SVG to PNG using canvas before uploading
- 2x scale for higher quality output
- Fix Word export compatibility issue (SVG not supported by python-docx)
- Update version to 1.4.1
- Update README.md and README_CN.md with new feature

docs/plugins/actions/index.zh.md

@@ -33,7 +33,7 @@ Actions 是交互式插件，能够：
 
     使用 AntV 可视化引擎，将文本转成专业的信息图。
 
-    **版本：** 1.4.0
+    **版本：** 1.4.1
 
     [:octicons-arrow-right-24: 查看文档](smart-infographic.md)