feat: 四圆角独立处理 + transform rotate

- 圆角：取四角最大值（PPT只支持统一圆角）
- 旋转：CSS transform:rotate → pptxgenjs rotate
- 两个文件同步

convert-w2p.js

@@ -826,13 +826,25 @@ async function convert(input) {
           shapeOpts.fill.transparency = Math.max(shapeOpts.fill.transparency || 0, opTrans);
         }
         
-        // 圆角
-        var brVal = n.styles.borderTopLeftRadius;
-        if (brVal && brVal !== '0px') {
-          if (brVal.includes('%')) {
-            shapeOpts.rectRadius = parseFloat(brVal) / 100;
-          } else {
-            shapeOpts.rectRadius = parseFloat(brVal) / 72;
+        // 圆角（取四角最大值，PPT 只支持统一圆角）
+        var brCorners = [
+          n.styles.borderTopLeftRadius,
+          n.styles.borderTopRightRadius,
+          n.styles.borderBottomLeftRadius,
+          n.styles.borderBottomRightRadius
+        ].filter(v => v && v !== '0px').map(v => {
+          if (v.includes('%')) return parseFloat(v) / 100;
+          return parseFloat(v) / 72;
+        });
+        if (brCorners.length > 0) {
+          shapeOpts.rectRadius = Math.max(...brCorners);
+        }
+        
+        // 旋转（CSS transform: rotate）
+        if (n.styles.transform && n.styles.transform !== 'none') {
+          var rotateMatch = n.styles.transform.match(/rotate\(([\d.]+)deg\)/);
+          if (rotateMatch) {
+            shapeOpts.rotate = parseFloat(rotateMatch[1]);
           }
         }
         
@@ -866,8 +878,8 @@ async function convert(input) {
         // 选择形状类型：圆角 >= 50% 且 w≈h 时用 ellipse（正圆），否则用 roundRect
         var useShape = 'rect';
         if (shapeOpts.rectRadius) {
-          var brPct = parseFloat(n.styles.borderTopLeftRadius);
-          var isCircle = (brPct >= 50 || (brPct.toString().includes('%') && parseFloat(brPct) >= 50)) && Math.abs(opts.w - opts.h) < 0.05;
+          var maxBrPct = Math.max(...brCorners.map(v => v * 72)); // 转回 px 参考
+          var isCircle = shapeOpts.rectRadius >= 0.5 && Math.abs(opts.w - opts.h) < 0.05;
           useShape = isCircle ? 'ellipse' : 'roundRect';
         }
         objects.push({ type: 'shape', shapeName: useShape, options: shapeOpts });
@@ -1042,6 +1054,7 @@ if (require.main === module) {
           else shapeOpts.line = { type: 'none' };  // 去掉 pptxgenjs 默认边框
           if (o.shadow) shapeOpts.shadow = o.shadow;
           if (o.rectRadius) shapeOpts.rectRadius = o.rectRadius;
+          if (o.rotate) shapeOpts.rotate = o.rotate;
           slide.addShape(pres.ShapeType[st] || pres.ShapeType.rect, shapeOpts);
         } else if (obj.type === 'image') {
           slide.addImage({