fix(composite): don't draw partially off-screen images (prevents sticky images on scroll)

app/compositeview.go

@@ -273,11 +273,11 @@ func (cc *compositeContent) drawImage(ctx *ui.Context, idx, row, width, height i
 		graphic.Resize(width, height)
 	}
 
-	startRow := row
-	if startRow < 0 {
-		startRow = 0
+	// Only draw when fully on-screen — partial placement causes sticky images
+	if row < 0 || row+height > ctx.Height() {
+		return
 	}
-	win := ctx.Window().New(0, startRow, width, height)
+	win := ctx.Window().New(0, row, width, height)
 	graphic.Draw(win)
 }