Fix element stacking by resetting autoplace state

Elements (text, dynamics) were stacking after edits because autoplace
collision detection used stale offset state. Clear autoplace state
(offsetChanged, changedPos) during layout reset to force fresh collision
detection without resetting positions.

Author: CubikingChill

src/engraving/dom/engravingitem.h

@@ -518,6 +518,8 @@ class EngravingItem : public EngravingObject
             m_mask.reset();
             //! NOTE Temporary removed, have problems, need investigation
             //m_pos.reset();
+            autoplace.offsetChanged = OffsetChange::NONE;
+            autoplace.changedPos = PointF();
         }
 
         virtual bool isValid() const { return m_shape.has_value() && m_shape.value().bbox().isValid(); }