gui: Make written-card groups match the paper layout #72

Tails 7.13 field-test finding: the Write it down view should present uppercase four-character card groups in the operator's reading/transcription order, using one line when space permits and wrapping only when necessary. Preserve card contents and existing secret-display protections.

Implemented in focused GUI PR #77 on top of #65/#66. Exact-head run 464 is green and the GUI remains within the authorized <2050 budget. Keep this issue open until the final GUI stack is rebased onto the settled library/CLI tip and #77 is integrated; include the normal Tails visual pass when freezing that candidate.