refactor: Implement typed error enums for all contracts

[cypriannwokolo2-creator]

Description

All contracts should use typed error enums with numeric codes instead of string-based error messages.

Requirements

• Define error enums with numeric codes for each contract
• Map all failure modes to error variants
• Add error classification module for Go backend integration
• Update tests to verify specific error codes

Acceptance Criteria

• All contracts use typed error enums
• Error codes are numeric and machine-readable
• Go backend can classify Soroban errors
• Tests verify specific error variants

Priority

Medium

[Teejay2696]

@Teejay2696 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I’m interested in contributing to this issue and believe I can deliver a clean, well-tested solution that aligns with the project’s standards.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Teejay2696 to this issue.

[baling-1]

@baling-1 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

hey maintainer kindly assign this to me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @baling-1 to this issue.

[Femaleotaku]

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

Hello, I'd like to pick this issue up.

This touches Soroban, which I have hands-on experience with. I'll restructure this carefully, preserving behavior while making the code easier to maintain.

Planned approach, based on the acceptance criteria:

• All contracts use typed error enums
• Error codes are numeric and machine-readable
• Go backend can classify Soroban errors
• Tests verify specific error variants

Happy to get started right away if assigned — looking forward to contributing.

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

[dimin4241-svg]

@dimin4241-svg has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I have hands-on Rust and Soroban experience with typed error enums and stable contract error surfaces. I reviewed this issue and can migrate the shipped contracts consistently, preserving numeric codes and updating callers and tests without broad refactoring. I can complete it within 1–2 days of assignment. Please assign it to me.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @dimin4241-svg to this issue.

[drips-wave]

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

🧑‍💻 @Femaleotaku: 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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