There is no way to let Cider check aliases

[aplteam]

If an alias was correctly established and then the project folder moved elsewhere, the alias points to a non-existent folder.

1. When the user asks for a list with all aliases (with [?]) or uses the wildcard syntax (like Foo*) then Cider should check all folders for existence (and maybe also for having a project config file) and mark those that fail the test.
2. There should be a way to ask Cider to remove all aliases that do not point to an existing folder.