Enabling timer for every command in the interpreter

It would be useful to have a flag which enables the timer (either time or elapsedTime) for every command entered directly in the interpreter, but I don't know where this should be placed.

Start by locating the interpreter entry point that handles commands entered directly and the existing `time` or `elapsedTime` behavior. Define where a persistent flag should be configured and verify that enabling it reports timing for every directly entered command without changing other command behavior.

Written by the indexing model from the issue text.