sdk: add getRound caching with explicit invalidation

[karagozemin]

Summary

Provide an optional short-lived cache for getRound / getConfig reads in SubRosaClient, with explicit invalidation on write operations (commit/reveal/settle).

Motivation

Dashboards and keeper watch loops re-read the same round repeatedly; uncached reads add avoidable RPC load and latency.

Acceptance criteria

• Opt-in cache with configurable TTL (default off).
• Writes invalidate the affected round entry.
• Tests proving stale reads are avoided after a write.
• Documented tradeoffs in the SDK README.

[Chigybillionz]

I can take this up and begin immediately

[Ajibose]

i would love to work on this

[ZuLu0890]

I would love to work on this issue

[egekoca]

Hi, I’d like to take this SDK issue. I work primarily in TypeScript and JavaScript and have built Stellar-facing utilities with unit-tested network and payment flows. I would add opt-in TTL caching for getRound and getConfig, targeted invalidation after commit, reveal, and settle, and cover disabled mode, hits and misses, expiry, and stale-read prevention before updating the SDK docs. Please assign me if this scope works.

Edit: My GitHub username has been restored to @egekoca; this application remains active.

[winsznx]

i have good experience with oss

[Ugooweb]

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

I am confident that I can implement this having worked on something similar in the past

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

[drips-wave]

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

🧑‍💻 @Ugooweb: 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.

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