Fix Prettier formatting issues

- Remove trailing whitespace and fix indentation in src/app.js
- Format whitespace in src/middleware/auth.js
- Fix formatting and add missing newline in src/middleware/browserFallback.js

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/middleware/auth.js

@@ -771,7 +771,7 @@ const corsMiddleware = (req, res, next) => {
 
   // 🆕 检查是否为Chrome插件请求
   const isChromeExtension = origin && origin.startsWith('chrome-extension://')
-  
+
   // 设置CORS头
   if (allowedOrigins.includes(origin) || !origin || isChromeExtension) {
     res.header('Access-Control-Allow-Origin', origin || '*')