* docs: replace sponsor block with CodeRabbit Replace the previous sponsor video and GitHub Sponsors block with a CodeRabbit sponsor link in the package README, docs homepage, and sponsors guide. Add the CodeRabbit brand logo assets from the official brand page, including a dark-background variant so the logo remains legible in VitePress dark mode and GitHub dark mode. The sponsor link now points to https://coderabbit.link/ryoppippi across the updated surfaces. * docs: keep sponsorkit sponsor circle Restore the existing sponsorkit sponsors.svg block after adding CodeRabbit, so only the previous YouTube featured sponsor is removed. Keep the homepage sponsors image centered with a flex wrapper while preserving the existing sponsors.svg source and GitHub Sponsors link. * docs: add sponsors image alt text Address CodeRabbit feedback by adding descriptive alt text to the restored sponsorkit sponsors.svg image in the package README and sponsors guide. * docs: use hosted sponsors image Replace the old jsDelivr sponsorkit image URL with the new hosted sponsors image at https://sponsors.ryoppippi.com/sponsors.png across the README and docs sponsor blocks. Keep the existing GitHub Sponsors links and alt text unchanged; only the image CDN source changes.