feat(platform): adopt hardened core contracts

shared/src/commonMain/kotlin/com/vnidrop/app/VniDropAppViewModel.kt

@@ -81,6 +81,11 @@ class VniDropAppViewModel(
 
 	private var selectedFile: PickedShareFile? = null
 
+	override fun onCleared() {
+		repository.shutdown()
+		super.onCleared()
+	}
+
 	init {
 		AppLogger.initialize(appDataDir)
 		AppLogger.info("lifecycle", "app started", mapOf("platform" to platformName))

shared/src/commonMain/kotlin/com/vnidrop/app/core/CoreRepository.kt

@@ -39,6 +39,12 @@ class CoreRepository(
 
 	private var core: VnidropCore? = null
 
+	fun shutdown() {
+		core?.shutdown()
+		core = null
+		_state.update { it.copy(isInitialized = false, status = "Not initialized") }
+	}
+
 	private val sink = object : CoreEventSink {
 		override fun onEvent(event: CoreEvent) {
 			_state.update { current ->

shared/src/commonMain/kotlin/com/vnidrop/app/ui/state/AppUiModels.kt

@@ -143,7 +143,7 @@ fun friendlyCoreError(raw: String?): String? {
 }
 
 private val progressPhases = setOf("import", "ticket", "access", "transfer", "download", "export", "lifecycle")
-private val activeTransferStatuses = setOf("sharing", "receiving")
+private val activeTransferStatuses = setOf("importing", "sharing", "receiving")
 
 private fun eventLabel(event: CoreEvent): String {
 	val direction = event.direction?.replaceFirstChar { it.uppercase() }