In the Send function, there are two consecutive validations for coin amounts that perform overlapping checks:
https://github.com/initia-labs/minievm/blob/0bc0c0f19de493c3c711f6f3d48e5befb0c48115/x/bank/keeper/msg_server.go#L50-L56
The IsValid() method already includes the positive amount check that IsAllPositive() performs, making the second check redundant. This creates unnecessary gas consumption for users sending transactions.
Also, the current implementation allows empty transfers (msg.Amount with length 0) to pass validation.
Replace the redundant validation with a single, comprehensive check. Something like:
