Add per-request timeout option to SplitClient constructor

[Kingsman-99]

Description

SplitClient uses the default HTTP timeout from the underlying fetch/axios adapter with no way to override it. Long-running Horizon queries can block the client indefinitely on slow networks.

Acceptance Criteria

• SplitClientOptions gains requestTimeoutMs?: number (default 30 000)
• All outgoing HTTP requests made by the client honour this timeout
• Timed-out requests throw a RequestTimeoutError with the configured limit in the message
• Unit tests pass

Context

• Target file: src/client/SplitClient.ts
• Per-call overrides are out of scope; the constructor-level default is sufficient

[0xApana]

@0xApana has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi, maintainer i'll like to work on this.

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[henrypeters]

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

Hi maintainer, I would love to work on this issue

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[drips-wave]

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

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[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox!

@henrypeters's PR #795 was approved and merged by @Kingsman-99.

🏆 @henrypeters: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (389 total points). Track your full progress on GrantFox.

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

[drips-wave]

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

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