Feature/rescue funds

[ifelsedeveloper]

Change Summary

What does this PR change?
Add Rescuable mixin (contracts/mixins/Rescuable.sol) and IRescuable interface (contracts/interfaces/IRescuable.sol) allowing contract owners to recover stuck ERC20 tokens and native ETH. Add RescuableMock and NoReceiveOwnerMock test helpers, and a full Hardhat test suite.

Related Issue/Ticket:
https://1inch.atlassian.net/browse/PT1-421

Testing & Verification

How was this tested?

• Unit tests
• Integration tests
• Manual testing (describe steps)
• Verified on staging

New test file test/contracts/Rescuable.test.ts covers:

• ERC20 token rescue by owner
• Partial ERC20 balance rescue
• Native ETH rescue by owner
• Partial ETH balance rescue
• Revert when called by non-owner (OwnableUnauthorizedAccount)
• Revert when ETH transfer fails (ETHTransferFailed)
• Revert when token transfer returns false (SafeTransferFailed)

All 8 tests pass.

Risk Assessment

Risk Level:

• Low - Minor changes, no operational impact
• Medium - Moderate changes, limited impact, standard rollback available
• High - Significant changes, potential operational impact, complex rollback

Risks & Impact

• New abstract mixin — no changes to existing contracts; adopters opt in by inheriting Rescuable.
• rescueFunds is onlyOwner-gated; no risk to user funds. Owner can only withdraw tokens/ETH held directly by the contract.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[BoogerWooger]

All ok