feat: v2.0 — 插件改造，集成 PPTX 导出

改造内容：
- 改名 Web to Pixso → Web to PPT
- 删除 pixso-plugin/、element-picker.js、popup-panel.js
- 新增 convert-browser.js（浏览器版转化逻辑）
- 新增 lib-pptxgen.js（pptxgenjs 浏览器 bundle）
- 重写 popup.js（触发捕获→转化→下载）
- 重写 background.js（缓存采集数据，支持 WEB_TO_PPT_GET_DATA）
- manifest.json 改名 + 添加 default_popup

流程：popup 点击导出 → background 抓取 DOM → popup 运行转化 → chrome.downloads 下载 PPTX

web-to-pixso/manifest.json

@@ -1,15 +1,16 @@
 {
   "manifest_version": 3,
-  "name": "Web to Pixso",
-  "version": "1.1.1",
-  "description": "Capture a webpage and convert it into editable Pixso layers.",
+  "name": "Web to PPT",
+  "version": "2.0.0",
+  "description": "Capture a webpage and export it as an editable PPTX presentation.",
   "permissions": ["activeTab", "scripting", "downloads", "storage"],
   "host_permissions": ["<all_urls>"],
   "background": {
     "service_worker": "background.js"
   },
   "action": {
-    "default_title": "Web to Pixso",
+    "default_title": "Web to PPT",
+    "default_popup": "popup.html",
     "default_icon": {
       "16": "logo/plugin-logo.png",
       "32": "logo/plugin-logo.png",
@@ -25,7 +26,7 @@
   },
   "web_accessible_resources": [
     {
-      "resources": ["capture.js", "runner.js", "element-picker.js", "popup-panel.js", "logo/plugin-logo.png"],
+      "resources": ["capture.js", "runner.js", "lib-pptxgen.js", "convert-browser.js"],
       "matches": ["<all_urls>"]
     }
   ]