fix(android): unblock protected-core startup on Android

Use flock for profile locks, hash secret record filenames under NAME_MAX,
and dismiss the starting overlay after the first init attempt.

Co-authored-by: Cursor <cursoragent@cursor.com>

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

@@ -255,7 +255,7 @@ fun App(
 				windowChrome?.invoke()
 				val startingLabel = stringResource(Res.string.app_starting)
 				AnimatedVisibility(
-					visible = !sendCoreState.isInitialized,
+					visible = !sendCoreState.isInitialized && !appState.startupSettled,
 					enter = fadeIn(),
 					exit = fadeOut(),
 				) {

shared/src/commonMain/kotlin/com/vnidrop/app/feature/app/AppViewModel.kt

@@ -21,6 +21,8 @@ import kotlinx.coroutines.launch
 data class AppState(
 	val destination: AppDestination = AppDestination.Send,
 	val themeMode: ThemeMode = ThemeMode.System,
+	/** True after the first core initialize attempt finishes (success or failure). */
+	val startupSettled: Boolean = false,
 )
 
 class AppGraphViewModel(dependencies: AppDependencies) : ViewModel() {
@@ -46,6 +48,7 @@ class AppViewModel(
 		viewModelScope.launch {
 			val relaySettings = preferencesRepository.preferences.first().relaySettings
 			repository.initialize(environment.defaultCoreDataDir, relaySettings).onFailure(messages::error)
+			_state.update { it.copy(startupSettled = true) }
 		}
 		viewModelScope.launch {
 			preferencesRepository.preferences.collect { preferences ->

shared/src/commonTest/kotlin/com/vnidrop/app/feature/ViewModelsTest.kt

@@ -80,6 +80,7 @@ class ViewModelsTest {
 		val viewModel = AppViewModel(environment(), core, preferences(), UiMessageController())
 		advanceUntilIdle()
 		assertTrue(core.state.value.isInitialized)
+		assertTrue(viewModel.state.value.startupSettled)
 		assertEquals(listOf(RelaySettings()), core.initializedRelaySettings)
 		viewModel.selectDestination(AppDestination.Settings)
 		assertEquals(AppDestination.Settings, viewModel.state.value.destination)