sync: convert-browser.js 同步 SVG 图标相关改动

- collectSlideChildren 保留 RECTANGLE+backgroundImages
- imageRects 包含 RECTANGLE+backgroundImages
- 图片处理：data URL 直接使用

web-to-ppt/convert-browser.js

@@ -76,7 +76,7 @@ function collectSlideChildren(node, slideX, slideY, parentW, depth) {
   const nr = node.rect;
   const rw = nr.width ?? nr.w;
   const rh = nr.height ?? nr.h;
-  if (node.type !== 'RECTANGLE' && node.layerGroup !== 'comparison') {
+  if ((node.type !== 'RECTANGLE' || (node.backgroundImages && node.backgroundImages.length > 0)) && node.layerGroup !== 'comparison') {
     results.push({
       id: node.id, type: node.type, name: node.name, tag: node.tag,
       rect: { x: nr.x - slideX, y: nr.y - slideY, w: rw, h: rh },
@@ -232,7 +232,7 @@ async function convertToPptx(input, onProgress) {
     sg.children.sort((a, b) => (parseInt(a.styles?.zIndex) || 0) - (parseInt(b.styles?.zIndex) || 0));
 
     // 重叠去重
-    const imageRects = sg.children.filter(c => c.type === 'IMAGE' && c.rect).map(c => ({
+    const imageRects = sg.children.filter(c => (c.type === 'IMAGE' || (c.type === 'RECTANGLE' && c.backgroundImages?.length > 0)) && c.rect).map(c => ({
       x: Math.round(c.rect.x), y: Math.round(c.rect.y),
       w: Math.round(c.rect.w), h: Math.round(c.rect.h),
       z: parseInt(c.styles?.zIndex) || 0
@@ -398,8 +398,14 @@ async function convertToPptx(input, onProgress) {
       if ((n.type === 'IMAGE' || n.type === 'RECTANGLE') && n.backgroundImages?.length > 0) {
         var imgKey = n.backgroundImages[0];
         var asset = assets[imgKey];
-        if (asset?.data) {
-          objects.push({ type: 'image', options: { x: opts.x, y: opts.y, w: opts.w, h: opts.h, data: asset.data } });
+        var imgData;
+        if (imgKey.startsWith('data:')) {
+          imgData = imgKey;
+        } else if (asset?.data) {
+          imgData = asset.data;
+        }
+        if (imgData) {
+          objects.push({ type: 'image', options: { x: opts.x, y: opts.y, w: opts.w, h: opts.h, data: imgData } });
         }
       }