gui: Keep card-count choices neutral #71

Tails 7.13 field-test finding: the create/restore card-count chooser should not label any preset “(recommended)”. Keep the existing choices and behavior otherwise unchanged; do not add backup-policy guidance here.

Implemented in focused GUI PR #77 on top of #65/#66. The #77 exact-head Python-package run 464 is green and the final GUI source remains within the authorized <2050 budget. Keep this issue open until the final GUI stack is rebased onto the settled library/CLI candidate and #77 is integrated; then close it with that integration.