feat: 加入 web-to-pixso 插件源码

Chrome 扩展，用于从网页提取 DOM 树为 JSON 格式。
核心文件：capture.js（76KB，提取逻辑）

web-to-pixso/manifest.json

@@ -0,0 +1,32 @@
+{
+  "manifest_version": 3,
+  "name": "Web to Pixso",
+  "version": "1.1.1",
+  "description": "Capture a webpage and convert it into editable Pixso layers.",
+  "permissions": ["activeTab", "scripting", "downloads", "storage"],
+  "host_permissions": ["<all_urls>"],
+  "background": {
+    "service_worker": "background.js"
+  },
+  "action": {
+    "default_title": "Web to Pixso",
+    "default_icon": {
+      "16": "logo/plugin-logo.png",
+      "32": "logo/plugin-logo.png",
+      "48": "logo/plugin-logo.png",
+      "128": "logo/plugin-logo.png"
+    }
+  },
+  "icons": {
+    "16": "logo/plugin-logo.png",
+    "32": "logo/plugin-logo.png",
+    "48": "logo/plugin-logo.png",
+    "128": "logo/plugin-logo.png"
+  },
+  "web_accessible_resources": [
+    {
+      "resources": ["capture.js", "runner.js", "element-picker.js", "popup-panel.js", "logo/plugin-logo.png"],
+      "matches": ["<all_urls>"]
+    }
+  ]
+}