Browser Profiling Platform-Specific Examples

**The Problem:** Frontend developers often can't control server headers. The docs say "configure your server to send this header" but don't give copy-paste examples.

**Solution:** 

Add hosting-specific snippets for:

* Vercel (vercel.json)
* Netlify (netlify.toml)
* Nginx
* AWS CloudFront
* Apache
* Express/Node.js