Converts the 120KB PNG logo to 17KB WebP (86% smaller). Both logo instances in the marketing layout use <picture> with WebP source and PNG fallback for maximum browser compatibility.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
