- Logic layer has separate ConfigChan and ScaleChan
- ConfigEvent: width/height in Dp, set on ConfigEvent
- ScaleEvent: scale factor, set on FrameEvent when scale changes
- Logic has ScreenSize() accessor for layout/rendering pipeline
- Logic has SetScale() to update scale and recompute layout
- main.go: ConfigEvent stores pixels, converts to DP using current scale
- main.go: FrameEvent gets actual scale, sends ScaleEvent if changed