ci: Add pre-commit hooks for Rust formatting and Clippy lints on contract changes

[Gbangbolaoluwagbemiga]

Description

The frontend uses Husky for pre-commit hooks (frontend/.husky/) but the Rust contracts have no pre-commit enforcement. Add hooks that run cargo fmt --check and cargo clippy on staged .rs files.

Acceptance Criteria

• Pre-commit hook script added
• cargo fmt --check runs on staged Rust files
• cargo clippy -- -D warnings runs on staged Rust files
• Hook skippable with --no-verify for emergencies

[janetobande]

@janetobande has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

I would like to work on this please, i have a strong experience in this aspect. Pls consider me to work on it.

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

[kulayddon]

@kulayddon has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

I have always respected this codebase, know how important security is, and i can handle this

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

[drips-wave]

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

🧑‍💻 @kulayddon: 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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[drips-wave]

This issue has been completed by @kulayddon as part of the Stellar Wave Program's 9th Wave 🥳

😎 @kulayddon: 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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