I'd recommend splitting commands.js into different files (cleaner coding practice see here for an example).

Ultimatley looks good though, another good practice is avoiding hard coding stuff, in your SSRPItems.cs is the file standing out to me thats hardcoded. Try using a data storing method and creating commands (could be specified to only a certain user or rank that can use this command) where you can add items which should be easier than editing the actual code to add more items. Just a suggestion though I know sometimes people prefer adding it via the code. A config file is also a nice touch to stop people from searching through all your code to modify specific values.