Implement SDK caching layer with configurable TTL for read-only queries

[p3ris0n]

Summary

Add an in-memory caching layer to the SDK for read-only contract queries to reduce RPC calls and improve dApp responsiveness.

Requirements

• Create sdk/src/cache.ts with CacheManager
• Implement LRU eviction with configurable TTL
• Automatic cache invalidation after write operations
• Support cache warming
• Add persistent cache via localStorage
• Cache hit/miss metrics

[jerrymusaga]

@jerrymusaga has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Please I will like to work on this issue

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

[drips-wave]

Congratulations, @jerrymusaga! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @jerrymusaga: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊