Parse Retry-After header with fractional seconds in RateLimitParser

[Kingsman-99]

Description

RateLimitParser parses the Retry-After header as an integer number of seconds using parseInt, which silently truncates fractional values (e.g., "1.5" becomes 1 s). Some Horizon nodes return sub-second retry hints.

Acceptance Criteria

• parseRetryAfter(value: string): number uses parseFloat and returns milliseconds
• HTTP-date format values are also handled and converted to a millisecond delay from now
• Values that cannot be parsed return null rather than NaN
• Unit tests pass

Context

• Target file: src/throttle/RateLimitParser.ts
• Return value unit is milliseconds throughout to match the rest of the throttle module

[heymide]

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

I can take this on. I've gone through the details and will provide a well-tested solution aligned with the project standards.

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

[Ebuka321]

@Ebuka321 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Good day can i work on these.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Ebuka321 to this issue.

[drips-wave]

Congratulations, @Ebuka321! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @Ebuka321: 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 🌊

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox!

@Ebuka321's PR #792 was approved and merged by @Kingsman-99.

🏆 @Ebuka321: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (850 total points). Track your full progress on GrantFox.

👏 Great work, @Ebuka321! Keep contributing to Stellar-split.

[drips-wave]

This issue has been completed by @Ebuka321 as part of the Stellar Wave Program's 8th Wave 🥳

😎 @Ebuka321: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

🧑‍💻 Repo maintainers: How'd the contributor do? Leave a review to share your experience working with them.