Add service worker caching for static assets

[king-aj-the-first]

Background: public/fallback-PPkJ6igsxJlxKyK41-Vd3.js suggests a service worker is partially configured. Static assets (fonts, icons, wallet SVGs) should be cached for offline support.

What "done" looks like:

• Service worker caches static assets on install using a cache-first strategy
• app/offline/page.tsx is served from cache when the user is offline
• Cache is versioned — new deploys invalidate old caches

Key files: public/, app/offline/page.tsx, next.config.js

Constraints:

• Do not cache API responses or contract calls in the service worker
• Must work alongside Next.js's default caching — do not conflict

PR must include: Service worker config + offline test + cache version strategy explanation.

[Vicistar-V]

@Vicistar-V has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I can work on this Please assign me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Vicistar-V to this issue.

[EDOHWARES]

@EDOHWARES has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

GM GM Maintainer, pls can I work on this issue ? ETA - 24hrs

ℹ️ Repo Maintainers: To accept this application, review their application or assign @EDOHWARES to this issue.

[drips-wave]

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

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