Generic SEO description on /defi

This page currently inherits OG description + images for the site overall rather than something specific for defi users that might be seeing it as a landing page preview on twitter or discord, preview doesn't currently tell you what the page is about

<img width="607" height="434" alt="Image" src="https://github.com/user-attachments/assets/53055794-b87e-482e-bdcc-c317819d666f" />