A real /load/index dump emits my_rotation_id as a bare number (0) for
unset MyRotation slots, which 400'd against the string? DTO field
(AllowReadingFromString only covers string->number). FlexibleStringConverter
accepts either form. Also skip empty deck slots (no cards) on import — a
dump carries every slot, mostly empty placeholders the client manages
itself.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Extends POST /admin/import_viewer to accept owned_cards (snapshot full-replace).
Unknown card_ids are skipped, counted in skipped_card_count on the response, and
logged server-side. Count is clamped to OwnedCardEntry.MaxCopies (3). Also injects
ILogger into AdminController and adds Cards/Items/Decks to the viewer reload graph.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>