fix(recurring): guard rescueTokens with nonReentrant

[LeoSlrRf]

Add rescueTokens function and zero-address fee validation to ERC20RecurringPaymentProxy

Adds a guard that reverts payment execution when feeAmount is non-zero but feeAddress is the zero address, preventing fees from being burned unintentionally.

Introduces a rescueTokens function allowing the contract owner to recover ERC20 tokens that have accumulated in the contract. The function enforces non-zero addresses for both the token and recipient, and is protected by onlyOwner and nonReentrant modifiers.

Tests cover:

• Revert when feeAmount > 0 and feeAddress is the zero address
• Successful token rescue by the owner
• Revert when a non-owner attempts to rescue tokens
• Revert when the rescue destination is the zero address

[LeoSlrRf]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• refactor(recurring): pack schedule state into one mapping #1762
• fix(recurring): grant and revoke relayer as separate calls #1761
• feat(recurring): emit schedule and admin events #1760
• test(recurring): accept and reject EIP-1271 batch signatures #1759
• feat(recurring): add revokeCycles for admitted bits #1758
• docs(recurring): warn cancel does not drop allowance #1757
• fix(recurring): reject zero-amount legs #1756
• fix(recurring): guard rescueTokens with nonReentrant #1755 👈 (View in Graphite)
• fix(recurring): bind batch schedule key to signed terms #1754
• fix(recurring): revert on a failed or short subscriber pull #1753
• feat(recurring): accept EIP-1271 smart-account signatures #1752
• fix(recurring): emit 8-byte payment references #1751
• master

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[greptile-apps]

Greptile Summary

The PR protects owner token rescues with the contract’s shared reentrancy guard and validates that nonzero fees have a nonzero destination.

• Adds an owner-only rescueTokens function with zero-address and transfer-result checks.
• Rejects recurring-payment permits that specify a nonzero fee without a fee recipient.
• Adds tests covering fee-recipient validation, successful residual-token rescue, access control, and zero-address rescue rejection.

Confidence Score: 5/5

The PR appears safe to merge with no actionable correctness or security defects identified.

The owner-only rescue operation shares the existing reentrancy guard with payment execution, validates both addresses, checks transfer success, and the fee-address check executes before funds or payment state are changed.

Important Files Changed

Filename	Overview
packages/smart-contracts/src/contracts/ERC20RecurringPaymentProxy.sol	Adds guarded owner token rescue and validates nonzero fee destinations before funds are pulled.
packages/smart-contracts/test/contracts/ERC20RecurringPaymentProxy.test.ts	Adds focused coverage for invalid fee destinations and rescue-token authorization and validation.

_{Reviews (1): Last reviewed commit: "fix(recurring): guard rescueTokens with ..." | Re-trigger Greptile}