Implement Soroban storage expiration tracking and renewal utilities

[Just-Bamford]

Description

Problem

Soroban storage entries have expiration requirements, but Sorokit does not provide a high-level mechanism for inspecting expiration state, estimating renewal requirements, or identifying storage approaching its expiration threshold.

Solution

Create storage expiration utilities that inspect contract entries, calculate their remaining lifetime, and generate renewal operations when required. Support configurable warning thresholds and optional automatic renewal workflows.

Acceptance Criteria

• calculateStorageRent(contractId) exposes estimated renewal requirements
• Storage entries can be evaluated for current and projected expiration
• renewContractStorage(contractId) builds the required renewal operation
• Configurable warning thresholds identify entries nearing expiration
• Auto-renewal can be explicitly enabled or disabled
• Renewal failures expose structured error information
• Tests cover active, near-expiry, expired, and renewal-failure scenarios
• APIs are exported through src/soroban/index.ts and src/index.ts

Note for Contributors

Keep estimation separate from transaction submission. Avoid assuming a fixed network rent value when the required information can be obtained dynamically. Test expiration calculations around boundary conditions.

[TechBroAfrica]

@TechBroAfrica has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi! I've gone through this issue and I'm confident I can implement a clean, maintainable solution that meets the acceptance criteria. I'll ensure it's thoroughly tested before submitting a PR. I'd appreciate being assigned this issue.

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

[mosharraftimes2018-dev]

@mosharraftimes2018-dev has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I would like to work on this issue

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[coderolisa]

@coderolisa has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello maintainer let me work on this
please assign

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[lajay-faith]

@lajay-faith has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello maintainer, I'd love to work on this issue

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[Machundii]

@Machundii has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi. I would like to work on this issue

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

[drips-wave]

Congratulations, @Machundii! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @Machundii: 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

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