Replace AppMigration11 by a dismissal when entering the login flow

AppMigration11 was run once, in the first release containing it, whatever
the state of the MultiAccount feature flag. Users installing the app
while the feature flag was disabled were considered as new users and
would never see the announcement once the feature flag got enabled.

The multi-account announcement is now pending by default (NeverShown),
and is marked as shown when the user enters the login flow while the
feature is enabled, either for the first time or to add another account.
Users who were already logged in before the feature became available
will see the announcement.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

appnav/src/main/kotlin/io/element/android/appnav/NotLoggedInFlowNode.kt

@@ -13,6 +13,7 @@ package io.element.android.appnav
 import android.os.Parcelable
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.lifecycle.lifecycleScope
 import coil3.SingletonImageLoader
 import coil3.annotation.DelicateCoilApi
 import com.bumble.appyx.core.lifecycle.subscribe
@@ -24,6 +25,8 @@ import dev.zacsweers.metro.AppScope
 import dev.zacsweers.metro.Assisted
 import dev.zacsweers.metro.AssistedInject
 import io.element.android.annotations.ContributesNode
+import io.element.android.features.announcement.api.Announcement
+import io.element.android.features.announcement.api.AnnouncementService
 import io.element.android.features.login.api.LoginEntryPoint
 import io.element.android.features.login.api.LoginParams
 import io.element.android.libraries.architecture.BackstackView
@@ -33,8 +36,11 @@ import io.element.android.libraries.architecture.callback
 import io.element.android.libraries.architecture.inputs
 import io.element.android.libraries.designsystem.utils.ForceOrientationInMobileDevices
 import io.element.android.libraries.designsystem.utils.ScreenOrientation
+import io.element.android.libraries.featureflag.api.FeatureFlagService
+import io.element.android.libraries.featureflag.api.FeatureFlags
 import io.element.android.libraries.matrix.ui.media.ImageLoaderHolder
 import io.element.android.services.analytics.api.watchers.AnalyticsColdStartWatcher
+import kotlinx.coroutines.launch
 import kotlinx.parcelize.Parcelize
 
 @ContributesNode(AppScope::class)
@@ -45,6 +51,8 @@ class NotLoggedInFlowNode(
     private val loginEntryPoint: LoginEntryPoint,
     private val imageLoaderHolder: ImageLoaderHolder,
     private val analyticsColdStartWatcher: AnalyticsColdStartWatcher,
+    private val featureFlagService: FeatureFlagService,
+    private val announcementService: AnnouncementService,
 ) : BaseFlowNode<NotLoggedInFlowNode.NavTarget>(
     backstack = BackStack(
         initialElement = NavTarget.Root,
@@ -68,6 +76,13 @@ class NotLoggedInFlowNode(
     override fun onBuilt() {
         super.onBuilt()
         analyticsColdStartWatcher.whenLoggingIn()
+        lifecycleScope.launch {
+            // Users who enter the login flow while the feature is available, either for the first time or to add
+            // another account, do not need to be informed about the multi-account feature.
+            if (featureFlagService.isFeatureEnabled(FeatureFlags.MultiAccount)) {
+                announcementService.onAnnouncementDismissed(Announcement.MultiAccount)
+            }
+        }
         lifecycle.subscribe(
             onResume = {
                 SingletonImageLoader.setUnsafe(imageLoaderHolder.get())

appnav/src/test/kotlin/io/element/android/appnav/RootFlowNodeTest.kt

@@ -141,6 +141,8 @@ class RootFlowNodeTest : RobolectricTest() {
                             loginEntryPoint = loginEntryPoint,
                             imageLoaderHolder = FakeImageLoaderHolder(),
                             analyticsColdStartWatcher = FakeAnalyticsColdStartWatcher(),
+                            featureFlagService = FakeFeatureFlagService(),
+                            announcementService = FakeAnnouncementService(),
                         )
                     }
                 )