fix: resize bug in retained mode

modules/LayoutEngine.lua

@@ -108,6 +108,8 @@ function LayoutEngine.new(props, deps)
     childrenCount = 0,
     containerWidth = 0,
     containerHeight = 0,
+    containerX = 0,
+    containerY = 0,
     childrenHash = "",
   }
 
@@ -1180,6 +1182,10 @@ function LayoutEngine:recalculateUnits(newViewportWidth, newViewportHeight)
   end
 
   -- Recalculate position if using viewport or percentage units
+  -- Skip position recalculation for flex children (non-explicitly-absolute children with a parent)
+  -- Their x/y is entirely controlled by the parent's layoutChildren() call
+  local isFlexChild = self.element.parent and not self.element._explicitlyAbsolute
+  if not isFlexChild then
     if self.element.units.x.unit ~= "px" then
       local parentWidth = self.element.parent and self.element.parent.width or newViewportWidth
       local baseX = self.element.parent and self.element.parent.x or 0
@@ -1227,6 +1233,7 @@ function LayoutEngine:recalculateUnits(newViewportWidth, newViewportHeight)
         self.element.y = self.element.units.y.value * scaleY
       end
     end
+  end
 
   -- Recalculate textSize if auto-scaling is enabled or using viewport/element-relative units
   if self.element.autoScaleText and self.element.units.textSize.value then
@@ -1504,6 +1511,8 @@ function LayoutEngine:_canSkipLayout()
   local childrenCount = #self.element.children
   local containerWidth = self.element.width
   local containerHeight = self.element.height
+  local containerX = self.element.x
+  local containerY = self.element.y
 
   -- Generate simple hash of children dimensions
   local childrenHash = ""
@@ -1520,6 +1529,8 @@ function LayoutEngine:_canSkipLayout()
     cache.childrenCount == childrenCount
     and cache.containerWidth == containerWidth
     and cache.containerHeight == containerHeight
+    and cache.containerX == containerX
+    and cache.containerY == containerY
     and cache.childrenHash == childrenHash
   then
     return true -- Layout hasn't changed, can skip
@@ -1529,6 +1540,8 @@ function LayoutEngine:_canSkipLayout()
   cache.childrenCount = childrenCount
   cache.containerWidth = containerWidth
   cache.containerHeight = containerHeight
+  cache.containerX = containerX
+  cache.containerY = containerY
   cache.childrenHash = childrenHash
 
   return false -- Layout has changed, must recalculate