Ok, autouse is of course ver elegant. I'd probably used something like the following, to save subroutne names.

my %actions = (
   'login'  => sub {
                require Login;
                do_login();
    },
    ...
);
[download]

But anyway, there's a slight problem about your code. Imagine somehow the "action" parameter is filled with nonsense, which should happen at least when you want to test your script. You'll get:

Use of uninitialized value in subroutine entry at ...
Can't use string ("") as a subroutine ref while "strict refs" in use a
+t .....
[download]

Simply because $query might contain "foo" (which does not exist in %actions). Just add a check to your code:

$query = 'default' unless exists $actions{ $query };
[download]

HTH.