Test accounts can't sign EIP712 messages

Test accounts can't sign EIP712 messages: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). I'm writing tests for a contract that uses EIP712 signatures (it's an ERC-2612 permit -style flow, so I need to construct a typed Permit message and have an account sign it)…