[SCF high][easy] Add HTLC timeout ordering guard

[karagozemin]

Goal\nPrevent swaps from starting with unsafe Ethereum and Stellar refund deadline ordering.\n\n## Acceptance criteria\n- Validate both chain deadlines before order creation.\n- Return a stable error for unsafe ordering.\n- Add equality and boundary tests.\n\n## Complexity\nHigh - small implementation, high reliability value.

[Adotse10066]

@Adotse10066 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I will love to work on this issue please. I deliver high impact solutions, ensuring seamless workflow and client satisfaction

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[The-Big-Danny]

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

hello, can i WORK on this issue?, i can fix it.

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[emirykl]

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

Hey, I want to take that issue

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[egekoca]

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

ı can do it

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[CemAyyildiz]

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

Can I work on this issue ?

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[drips-wave]

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

🧑‍💻 @CemAyyildiz: 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.

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