No you are not being dense at all ...
It originally used the moodle code directory.
Then moved to moodledata/mdeploy/ - right where one could easily see/find it ... included
a mdeploy.log - which I would tail -f when using.
And now moved again ... deeper into moodledata/temp/core_plugin/code_manager/
Prefer git for installations and updates to the core code myself ... would love to do the same for all addons, but have had trouble finding the 'right' code git repo for addons at one time.
Would be nice to see that git URL somewhere but understand that might be a future improvement way on down the road.
'spirit of sharing', Ken