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]

Hi, I’ve reviewed this issue and I’m confident I can fix it. I’d like to take it on.

[Chigybillionz]

I can take this up and begin immediately

[Phantomcall]

Hi! I'd like to work on this enhancement.

I have experience building TypeScript SDKs with caching layers and ensuring cache consistency around read/write operations. My goal is to implement a lightweight, opt-in cache that improves performance without changing existing SDK behavior.

My implementation plan is to:

• Add an optional in-memory cache for getRound and getConfig with a configurable TTL, leaving caching disabled by default to preserve backward compatibility.

• Cache read results only when enabled.

• Invalidate affected cache entries automatically after state-changing operations such as commit, reveal, and settle.

• Keep cache invalidation targeted so unrelated cached entries remain valid.

• Add comprehensive tests covering:

  • Cache hit/miss behavior
  • TTL expiration
  • Default (disabled) behavior
  • Automatic invalidation after write operations
  • Verification that stale data is never returned following a successful write

• Update the SDK README to document configuration, usage, cache semantics, and the tradeoffs between reduced RPC calls and temporary data freshness.

I'll keep the implementation focused, maintain backward compatibility, ensure the full test suite passes, and reference the issue in the PR.

I'd be happy to work on this once assigned. Thanks!

[Ajibose]

i would love to work on this

[ZuLu0890]

I would love to work on this issue