Refine homepage support links

[yvette-carlisle]

Summary

• remove repeated non-clickable hero/status links from the homepage header and hero overlay
• keep the Yvette X follow action beside the download CTA only
• add a single creator-support section explaining the free software support model
• raise the fixed header above the page content so the GitHub link is actually clickable

Validation

• node --check site/main.js
• git diff --check
• local static preview at http://127.0.0.1:4173/
• clicked the header GitHub link in the in-app browser and verified it navigates to https://github.com/hack-ink/rsnap