Implement build_price_message() byte layout

[AbelOsaretin]

Description\npassphrase || ledger_seq || token || min || max || timestamp.\n\n## Acceptance Criteria\n- [ ] Correct byte order

[Olorunfemi20]

@Olorunfemi20 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi, I'd like to work on this issue. I'm a full-stack developer with experience in Rust, binary serialization, and protocol design, and I can implement build_price_message() to produce the required deterministic byte layout. I'll ensure the message is encoded in the exact order—passphrase || ledger_seq || token || min || max || timestamp—with the correct byte ordering and consistent serialization for each field. I'll also add comprehensive unit tests covering normal cases and edge cases to verify the byte layout against the specification and ensure the implementation remains stable for signing and verification workflows.

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[dahmeezy]

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

I would love to work on this issue, please assign it to me

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[Oluwatomilola]

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

Hi, I would like to fix this.
I have sufficient experience fixing related issues.

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[chiscookeke11]

@chiscookeke11 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I’m interested in this issue and believe my experience with contracts, backend systems, and frontend implementation makes me a good fit. Happy to provide updates as I work through it.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @chiscookeke11 to this issue.

[drips-wave]

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

🧑‍💻 @Oluwatomilola: 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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[grantfox-oss]

🦊 GrantFox — @Oluwatomilola has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #385)
2. Your PR will be reviewed by the SO4-Markets maintainers

Good luck! Track your progress on GrantFox.

[drips-wave]

This issue has been completed by @Oluwatomilola as part of the Stellar Wave Program's 6th Wave 🥳

😎 @Oluwatomilola: 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.

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