[Client] Show horizontal art for plane and siege cards in the profile banner (#7118)

Use the landscape orientation flag to rotate sideways-layout card art
upright before cropping, so planes/sieges show their horizontal art as
the server profile banner card instead of a rotated full card.

- Curve cropCardArt around the card's landscapeOrientation flag with
  landscape-specific art margins (mirrors CardInfoPictureWidget)
- Add shared CardArtUtils::rotateSidewaysLayoutArt helper and apply it
  to the playmat (game render and settings preview) and card info widget,
  replacing three duplicate 90-degree rotation blocks

cockatrice/src/interface/widgets/cards/card_art_utils.h

@@ -0,0 +1,25 @@
+#ifndef CARD_ART_UTILS_H
+#define CARD_ART_UTILS_H
+
+#include <QPixmap>
+
+class ExactCard;
+
+namespace CardArtUtils
+{
+/**
+ * @brief Rotates a card's art upright when its layout shows sideways.
+ *
+ * Sideways-layout cards (planes, sieges/battles, split cards) store their
+ * landscape artwork rotated 90° inside a portrait frame. Art-crop displays,
+ * playmat art, and the card-info picture must show such art upright before
+ * sampling or painting. Portrait cards are returned unchanged.
+ *
+ * @param art The card pixmap to orient.
+ * @param card The card describing the art orientation.
+ * @return @p art rotated 90° clockwise for sideways-layout cards, else @p art.
+ */
+QPixmap rotateSidewaysLayoutArt(const QPixmap &art, const ExactCard &card);
+} // namespace CardArtUtils
+
+#endif // CARD_ART_UTILS_H