List ALL posts within last week from current category on category page

If I’m understanding you correctly you just need two more arguments in your $args array.

Firstly, category_name – see WP_Query – Category Parameter. We get the value from the $wp_query global via get_query_var(), so like this:

'category_name' => get_query_var( 'category_name' )

Secondly, for the number of posts to show there is posts_per_page as it is an archive one could actually use posts_per_archive_page – see WP_Query – Pagination Parameters.

So do either:

'posts_per_page' => -1

Or do:

'posts_per_archive_page' => -1