add: coin purchases + donator badge

crates/app/src/public/html/stacks/add_user.lisp

@@ -16,7 +16,7 @@
             (span (text "Select a stack to add this user to:"))
             (text "{% for stack in stacks %}")
             (button
-                ("class" "justify-start lowered w_full")
+                ("class" "justify_start lowered w_full")
                 ("onclick" "choose_stack('{{ stack.id }}')")
                 (icon (text "layers"))
                 (text "{{ stack.name }}"))