Add reentrancy-safe state updates before token transfers in slash_on_miss and claim in accountability_vault

[1nonlypiece]

Add reentrancy-safe state updates before token transfers in slash_on_miss and claim in accountability_vault

Description

In contracts/accountability_vault/src/lib.rs, slash_on_miss and claim transfer the SEP-41 token before persisting the updated Vault status. Reorder to a checks-effects-interactions pattern so the vault is marked Failed/Completed and staked zeroed in storage before the external token::Client::transfer call. Add tests in contracts/accountability_vault/src/test.rs proving the terminal state is committed even under a failing transfer.

Requirements and context

• Must be secure, tested, and documented
• Should be efficient and easy to review
• Apply checks-effects-interactions in slash_on_miss and claim in contracts/accountability_vault/src/lib.rs
• Zero staked and set status before token::Client::transfer
• Add a re-entrancy/ordering test in contracts/accountability_vault/src/test.rs
• Document the invariant in contracts/README.md

Suggested execution

• Fork the repo and create a branch
• git checkout -b feat/cei-ordering
• Implement changes
  • Modify contracts/accountability_vault/src/lib.rs
  • Add test cases to contracts/accountability_vault/src/test.rs
  • Update contracts/README.md
  • Add inline safety comments
• Test and commit
  • Run tests, cover edge cases
  • Include test output and notes

Example commit message

feat: apply checks-effects-interactions to vault payouts

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours

[Andreschuks101]

@Andreschuks101 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

This looks like I can resolve immediately. Please assign

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[drips-wave]

Congratulations, @Andreschuks101! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @Andreschuks101: 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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