Make regV5 resumable if the app closes.

demo/registration/src/main/java/org/signal/registration/sample/debug/NetworkDebugOverlay.kt

@@ -69,7 +69,7 @@ fun NetworkDebugOverlay(
       onClick = { showDialog = true },
       dragOffset = dragOffset,
       onDrag = { delta -> dragOffset += delta },
-      modifier = Modifier.align(Alignment.CenterEnd)
+      modifier = Modifier.align(Alignment.TopEnd)
     )
 
     if (showDialog) {

demo/registration/src/main/java/org/signal/registration/sample/screens/main/MainScreen.kt

@@ -14,7 +14,9 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
@@ -74,6 +76,7 @@ fun MainScreen(
   Column(
     modifier = modifier
       .fillMaxSize()
+      .verticalScroll(rememberScrollState())
       .padding(24.dp),
     horizontalAlignment = Alignment.CenterHorizontally,
     verticalArrangement = Arrangement.Center
@@ -95,6 +98,30 @@ fun MainScreen(
       Spacer(modifier = Modifier.height(32.dp))
     }
 
+    if (state.pendingFlowState != null) {
+      PendingFlowStateCard(state.pendingFlowState)
+      Spacer(modifier = Modifier.height(16.dp))
+
+      Button(
+        onClick = { onEvent(MainScreenEvents.LaunchRegistration) },
+        modifier = Modifier.fillMaxWidth()
+      ) {
+        Text("Resume Registration")
+      }
+
+      TextButton(
+        onClick = { showClearDataDialog = true },
+        modifier = Modifier.fillMaxWidth(),
+        colors = ButtonDefaults.textButtonColors(
+          contentColor = MaterialTheme.colorScheme.error
+        )
+      ) {
+        Text("Clear Pending Data")
+      }
+
+      Spacer(modifier = Modifier.height(16.dp))
+    }
+
     if (state.existingRegistrationState != null) {
       if (state.registrationExpired) {
         Row(
@@ -150,7 +177,7 @@ fun MainScreen(
       ) {
         Text("Clear All Data")
       }
-    } else {
+    } else if (state.pendingFlowState == null) {
       Button(
         onClick = { onEvent(MainScreenEvents.LaunchRegistration) },
         modifier = Modifier.fillMaxWidth()
@@ -213,6 +240,55 @@ private fun RegistrationField(label: String, value: String) {
   }
 }
 
+@Composable
+private fun PendingFlowStateCard(pending: MainScreenState.PendingFlowState) {
+  Card(
+    modifier = Modifier.fillMaxWidth(),
+    colors = CardDefaults.cardColors(
+      containerColor = MaterialTheme.colorScheme.tertiaryContainer
+    )
+  ) {
+    Column(
+      modifier = Modifier.padding(16.dp)
+    ) {
+      Text(
+        text = "In-Progress Registration",
+        style = MaterialTheme.typography.titleMedium,
+        color = MaterialTheme.colorScheme.onTertiaryContainer
+      )
+
+      HorizontalDivider(modifier = Modifier.padding(vertical = 8.dp))
+
+      RegistrationField(label = "Current Screen", value = pending.currentScreen)
+      RegistrationField(label = "Backstack Depth", value = pending.backstackSize.toString())
+      if (pending.e164 != null) {
+        RegistrationField(label = "Phone Number", value = pending.e164)
+      }
+      RegistrationField(label = "Has Session", value = if (pending.hasSession) "Yes" else "No")
+      RegistrationField(label = "Has AEP", value = if (pending.hasAccountEntropyPool) "Yes" else "No")
+    }
+  }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun MainScreenWithPendingFlowStatePreview() {
+  Previews.Preview {
+    MainScreen(
+      state = MainScreenState(
+        pendingFlowState = MainScreenState.PendingFlowState(
+          e164 = "+15551234567",
+          backstackSize = 4,
+          currentScreen = "VerificationCodeEntry",
+          hasSession = true,
+          hasAccountEntropyPool = false
+        )
+      ),
+      onEvent = {}
+    )
+  }
+}
+
 @Preview(showBackground = true)
 @Composable
 private fun MainScreenPreview() {

demo/registration/src/main/java/org/signal/registration/sample/screens/main/MainScreenState.kt

@@ -7,8 +7,17 @@ package org.signal.registration.sample.screens.main
 
 data class MainScreenState(
   val existingRegistrationState: ExistingRegistrationState? = null,
-  val registrationExpired: Boolean = false
+  val registrationExpired: Boolean = false,
+  val pendingFlowState: PendingFlowState? = null
 ) {
+  data class PendingFlowState(
+    val e164: String?,
+    val backstackSize: Int,
+    val currentScreen: String,
+    val hasSession: Boolean,
+    val hasAccountEntropyPool: Boolean
+  )
+
   data class ExistingRegistrationState(
     val phoneNumber: String,
     val aci: String,

demo/registration/src/main/java/org/signal/registration/sample/screens/main/MainScreenViewModel.kt

@@ -12,9 +12,11 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
+import kotlinx.serialization.json.Json
 import org.signal.core.util.Base64
 import org.signal.core.util.logging.Log
 import org.signal.registration.NetworkController
+import org.signal.registration.PersistedFlowState
 import org.signal.registration.StorageController
 import org.signal.registration.sample.storage.RegistrationPreferences
 
@@ -75,6 +77,7 @@ class MainScreenViewModel(
         } else {
           null
         },
+        pendingFlowState = loadPendingFlowState(),
         registrationExpired = false
       )
 
@@ -84,6 +87,27 @@ class MainScreenViewModel(
     }
   }
 
+  private suspend fun loadPendingFlowState(): MainScreenState.PendingFlowState? {
+    return try {
+      val data = storageController.readInProgressRegistrationData()
+      if (data.flowStateJson.isEmpty()) return null
+
+      val json = Json { ignoreUnknownKeys = true }
+      val persisted = json.decodeFromString(PersistedFlowState.serializer(), data.flowStateJson)
+
+      MainScreenState.PendingFlowState(
+        e164 = persisted.sessionE164,
+        backstackSize = persisted.backStack.size,
+        currentScreen = persisted.backStack.lastOrNull()?.let { it::class.simpleName } ?: "Unknown",
+        hasSession = persisted.sessionMetadata != null,
+        hasAccountEntropyPool = data.accountEntropyPool.isNotEmpty()
+      )
+    } catch (e: Exception) {
+      Log.w(TAG, "Failed to load pending flow state", e)
+      null
+    }
+  }
+
   private suspend fun checkRegistrationStatus() {
     when (val result = networkController.getSvrCredentials()) {
       is NetworkController.RegistrationNetworkResult.Success -> {