Virtualize the unbounded social ActivityFeed list

[RUKAYAT-CODER]

Overview
src/components/social/ActivityFeed.tsx (lines 59-95) maps every grouped activity into the DOM with an IntersectionObserver appending more indefinitely, so the node count grows without bound and causes scroll jank on long sessions. Windowing/virtualization should cap the rendered node count.

[udoyechinenyevictoria]

@udoyechinenyevictoria has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello! Please can I work on this issue?

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[Kleo-Crypt]

@Kleo-Crypt has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi, I’ve reviewed the issue carefully and I’m confident I can provide a clean, well-structured solution.

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Congratulations, @jaynomyaro! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

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