feat(command-zone): add graphics implementation with integration tests

Implement CommandZone - the main Qt graphics class for rendering and
interacting with command zones.

This commit brings together all previous components:
- Uses CommandZoneState for visibility management
- Uses CommandZoneLogic for card data handling
- Uses ZoneToggleButton for visibility controls
- Uses CommanderTaxCounter for tax display
- Uses z_values.h for proper visual layering

Zone modifications for command zone support:
- SelectZone: add command zone to zone selection
- StackZone: support command zone in stack operations
- TableZone: command zone positioning integration
- ViewZoneWidget: command zone viewing support

Integration tests verify:
- Counter parenting behavior
- Zone state coordination
- Full graphics stack interaction

cockatrice/src/game/zones/stack_zone.cpp

@@ -33,6 +33,11 @@ QRectF StackZone::boundingRect() const
 void StackZone::paint(QPainter *painter, const QStyleOptionGraphicsItem * /*option*/, QWidget * /*widget*/)
 {
     QBrush brush = themeManager->getExtraBgBrush(ThemeManager::Stack, getLogic()->getPlayer()->getZoneId());
+
+    // Set brush origin to compensate for zone position, keeping texture fixed in scene coordinates
+    QPointF scenePos = pos();
+    painter->setBrushOrigin(-scenePos);
+
     painter->fillRect(boundingRect(), brush);
 }
 
@@ -106,3 +111,11 @@ void StackZone::reorganizeCards()
     }
     update();
 }
+
+void StackZone::setHeight(qreal newHeight)
+{
+    prepareGeometryChange();
+    zoneHeight = newHeight;
+    reorganizeCards();
+    update();
+}