docs: tighten kotlin support examples

skills/compose-multiplatform-patterns/SKILL.md

@@ -252,11 +252,12 @@ val showScrollToTop by remember {
 // BAD — new lambda and list every recomposition
 items.filter { it.isActive }.forEach { ActiveItem(it, onClick = { handle(it) }) }
 
-// GOOD — remember filtered list, stable lambda with key
+// GOOD — key each item so callbacks stay attached to the right row
 val activeItems = remember(items) { items.filter { it.isActive } }
 activeItems.forEach { item ->
-    val onClick = remember(item.id) { { handle(item) } }
-    ActiveItem(item, onClick = onClick)
+    key(item.id) {
+        ActiveItem(item, onClick = { handle(item) })
+    }
 }
 ```