In the EvolvingProteus.constructor the duration is passed in as an input parameter. Function duration denotes the total duration of the curves evolution. Hence, the duration variable is a critical variable of the protocol. If duration is set to zero by mistake, it will prompt a redeployment of the contract which could be waste of gas and additional workload. An input validity check should be performed for the duration variable inside the constructor as follows:
https://github.com/code-423n4/2023-08-shell/blob/main/src/proteus/EvolvingProteus.sol#L243-L263
Note from the judge: for a more detailed description of this finding, please see issue 118 from warden lsaudit
