Validate SDK configuration at instantiation and surface clear errors

[Kingsman-99]

Overview

Invalid SDK configuration (missing contract ID, bad RPC URL format, conflicting options) is currently discovered at call time, leading to cryptic errors. Add upfront validation on new StellarSplitSDK(config).

Acceptance Criteria

• Constructor validates all config fields synchronously on instantiation
• Throws InvalidConfigError with a descriptive message for each failure case:
  • Missing or empty contractId
  • rpcUrl not a valid URL
  • network is not 'testnet' | 'mainnet' | a valid CustomNetwork object
  • rateLimit.requestsPerSecond ≤ 0
  • cache.ttl values are negative
  • rpcPoolSize outside the range 1–20
• InvalidConfigError lists all violations at once (not just the first)
• Config validation is synchronous — no async checks in the constructor
• TypeScript types for config are strict enough to catch most errors at compile time
• Unit tests cover every validation rule

[BigElv]

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

Hi maintainer I would love to work on this issue please

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

[abikedaniel22]

@abikedaniel22 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hello maintainer I'll like to work on this issue please can you assign me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @abikedaniel22 to this issue.

[uzochukwuV]

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

I'd love to work on this issue

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

[Malcolm-Wander]

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

Hello maintainer,I’d love to work on this issue please…promise to do bad accurate and swift job,thank you.

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

[wowamaxe-glitch]

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

I'm a full-stack developer and I'd like to take this issue.
I understand the requirements and will follow the existing project structure, keep the implementation clean, and include proper tests where applicable.

ETA: 1–3 days (depending on scope)

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

[drips-wave]

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

🧑‍💻 @wowamaxe-glitch: 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 🌊