feat: add avatar support and update dependencies

- Added avatar configuration to the author section in config.example.json and README.md.
- Integrated @radix-ui/react-avatar package for avatar rendering in the MasonryHeaderMasonryItem component.
- Updated pnpm-lock.yaml and package.json to include @radix-ui/react-avatar dependency.
- Removed loading text from index.html for a cleaner UI.
- Adjusted photo-loader.ts to use the workdir for manifest path.

Signed-off-by: Innei <tukon479@gmail.com>

README.md

@@ -130,13 +130,14 @@ cp config.example.json config.json
   "title": "我的照片画廊",
   "description": "记录生活中的美好瞬间",
   "url": "https://gallery.example.com",
-  "accentColor": "#007bff",
+  "accentColor": "#007bff", // 可选, 设置主题色
   "author": {
-    "name": "Your Name",
-    "url": "https://example.com"
+    "name": "Your Name", // 必填, 设置作者名称
+    "url": "https://example.com", // 可选, 设置作者主页
+    "avatar": "https://example.com/avatar.png" // 可选, 设置作者头像
   },
   "social": {
-    "twitter": "@yourusername"
+    "twitter": "@yourusername" // 可选, 设置社交账号
   }
 }
 ```