Enable multi-signature support for contracts

[Idrhas]

Introduce robust multi-signature support into the project to secure sensitive or high-value contract operations. The system should enable contract creators to require multiple signatures from predefined parties before a contract function can be executed or certain state changes are allowed. This feature should include intuitive configuration, signature validation, and informative error messages when approval conditions are not met. Multi-signature controls boost contract security and foster trust among users.

[chiemezie1]

@chiemezie1 has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

Hey! I'd like to pick up issue #103 — multi-signature support for contract operations.

I'll add a MultiSigConfig struct (signers list + threshold) to contract storage, a reusable assert_multisig_approved guard applied to sensitive state transitions, require_auth() validation per signer, and descriptive errors (InsufficientSignatures, UnauthorizedSigner, InvalidThreshold) for failed approval conditions. Tests will cover the threshold boundary, unauthorized signers, and unaffected non-gated functions.

Can you assign this to me? Thanks!

ℹ️ Repo Maintainers: To accept this application, review their application or assign @chiemezie1 to this issue.

[farouqyakubu6-creator]

@farouqyakubu6-creator has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

Implement a multi-signature system for contracts, requiring multiple authorized signers to approve critical functions or state changes. Features include easy signer configuration, threshold-based signature validation, and clear errors when approvals are insufficient. This ensures high-value operations are secure and builds user trust.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @farouqyakubu6-creator to this issue.

[drips-wave]

Congratulations, @farouqyakubu6-creator! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on March 30, 2026.

🧑‍💻 @farouqyakubu6-creator: 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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