feat(command-zone): add game creation UI

Implement UI components for configuring command zones when creating
new games.

New components:
- GameZoneOptionsWidget: reusable widget for zone configuration
- DlgLocalGameOptions: local game setup with command zone options

Integration points:
- DlgCreateGame: add command zone options to game creation dialog
- WindowMain: wire up command zone configuration in game flow

This allows players to:
- Enable/disable command zones for a game
- Select zone type (Commander, Companion, etc.)
- Configure zone-specific options

cockatrice/src/interface/widgets/dialogs/game_zone_options_widget.h

@@ -0,0 +1,67 @@
+/**
+ * @file game_zone_options_widget.h
+ * @ingroup RoomDialogs
+ * @brief Reusable widget for Commander format zone options.
+ *
+ * This widget encapsulates the zone enable/disable checkboxes used in both
+ * DlgCreateGame and DlgLocalGameOptions. It provides a simple interface
+ * while hiding settings persistence details.
+ */
+
+#ifndef GAME_ZONE_OPTIONS_WIDGET_H
+#define GAME_ZONE_OPTIONS_WIDGET_H
+
+#include <QWidget>
+
+class QCheckBox;
+class QVBoxLayout;
+
+/**
+ * @class GameZoneOptionsWidget
+ * @brief Widget for configuring Commander format zone options.
+ *
+ * Provides checkboxes for enabling command zone, companion zone, and
+ * background zone. Handles settings persistence internally, so callers
+ * don't need to know about SettingsCache keys or default values.
+ */
+class GameZoneOptionsWidget : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit GameZoneOptionsWidget(QWidget *parent = nullptr);
+
+    [[nodiscard]] bool enableCommandZone() const;
+    [[nodiscard]] bool enableCompanionZone() const;
+    [[nodiscard]] bool enableBackgroundZone() const;
+
+    void setCommandZoneEnabled(bool enabled);
+    void setCompanionZoneEnabled(bool enabled);
+    void setBackgroundZoneEnabled(bool enabled);
+
+    void loadFromSettings();
+    void saveToSettings();
+    void resetToDefaults();
+
+    void setReadOnly(bool readOnly);
+
+    QCheckBox *getCommandZoneCheckBox() const
+    {
+        return enableCommandZoneCheckBox;
+    }
+    QCheckBox *getCompanionZoneCheckBox() const
+    {
+        return enableCompanionZoneCheckBox;
+    }
+    QCheckBox *getBackgroundZoneCheckBox() const
+    {
+        return enableBackgroundZoneCheckBox;
+    }
+
+private:
+    QCheckBox *enableCommandZoneCheckBox;
+    QCheckBox *enableCompanionZoneCheckBox;
+    QCheckBox *enableBackgroundZoneCheckBox;
+};
+
+#endif // GAME_ZONE_OPTIONS_WIDGET_H