compose-multiplatform-patterns

# Compose Multiplatform Patterns Patterns for building shared UI across Android, iOS, Desktop, and Web using Compose Multiplatform and Jetpack Compose. Covers state management, navigation, theming, and performance. ## When to Activate - Building Compose UI (Jetpack Compose or Compose Multiplatform) - Managing UI state with ViewModels and Compose state - Implementing navigation in KMP or Android projects - Designing reusable composables and design systems - Optimizing recomposition and rendering performance ## State Management ### ViewModel + Single State Object Use a single data class for screen state. Expose it as `StateFlow` and collect in Compose: ```kotlin data class ItemListState( val items: List<Item> = emptyList(), val isLoading: Boolean = false, val error: String? = null, val searchQuery: String = "" ) class ItemListViewModel( private val getItems: GetItemsUseCase ) : ViewModel() { private val _state = MutableStateFlow(ItemListState()) val state: StateFlow<ItemListState> = _state.asStateFlow() fun onSearch(query: String) { _state.update { it.copy(searchQuery = query) } loadItems(query) } private fun loadItems(query: String) { viewModelScope.launch { _state.update { it.copy(isLoading = true) } getItems(query).fold( onSuccess = { items -> _state.update { it.copy(items = items, isLoading = false) } }, onFailure = { e -> _state.update { it.copy...