Create AppMigration09 to remove the cached well-known config from the SDK (#6026)

This value was most likely was incorrectly cached due to a previous issue in the SDK

features/migration/impl/src/main/kotlin/io/element/android/features/migration/impl/migrations/AppMigration09.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.features.migration.impl.migrations
+
+import dev.zacsweers.metro.AppScope
+import dev.zacsweers.metro.ContributesIntoSet
+import dev.zacsweers.metro.Inject
+import io.element.android.libraries.matrix.api.MatrixClientProvider
+import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.libraries.sessionstorage.api.SessionStore
+
+/**
+ * Ensure we clear the well-known cached config, since it could be invalid due to an SDK issue.
+ */
+@ContributesIntoSet(AppScope::class)
+@Inject
+class AppMigration09(
+    private val sessionStore: SessionStore,
+    private val matrixClientProvider: MatrixClientProvider,
+) : AppMigration {
+    override val order: Int = 9
+
+    override suspend fun migrate(isFreshInstall: Boolean) {
+        if (isFreshInstall) return
+
+        val sessions = sessionStore.getAllSessions()
+
+        for (session in sessions) {
+            val client = matrixClientProvider.getOrRestore(SessionId(session.userId)).getOrNull() ?: continue
+            client.resetWellKnownConfig()
+        }
+    }
+}

features/migration/impl/src/test/kotlin/io/element/android/features/migration/impl/migrations/AppMigration09Test.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.features.migration.impl.migrations
+
+import io.element.android.libraries.matrix.api.MatrixClient
+import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.libraries.matrix.test.FakeMatrixClient
+import io.element.android.libraries.matrix.test.FakeMatrixClientProvider
+import io.element.android.libraries.sessionstorage.test.InMemorySessionStore
+import io.element.android.libraries.sessionstorage.test.aSessionData
+import io.element.android.tests.testutils.lambda.lambdaRecorder
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+
+class AppMigration09Test {
+    @Test
+    fun `migration on fresh install does nothing`() = runTest {
+        val sessionStore = InMemorySessionStore(initialList = listOf(aSessionData()))
+        val getClientLambda = lambdaRecorder<SessionId, Result<MatrixClient>> { Result.success(FakeMatrixClient()) }
+        val clientProvider = FakeMatrixClientProvider(getClient = getClientLambda)
+        val migration = AppMigration09(sessionStore, clientProvider)
+        migration.migrate(isFreshInstall = true)
+
+        getClientLambda.assertions().isNeverCalled()
+    }
+
+    @Test
+    fun `migration on upgrade should invoke the resetWellKnownConfig method`() = runTest {
+        val sessionStore = InMemorySessionStore(initialList = listOf(aSessionData()))
+        val resetWellKnownLambda = lambdaRecorder<Result<Unit>> { Result.success(Unit) }
+        val getClientLambda = lambdaRecorder<SessionId, Result<MatrixClient>> {
+            Result.success(FakeMatrixClient(resetWellKnownConfigLambda = resetWellKnownLambda))
+        }
+        val clientProvider = FakeMatrixClientProvider(getClient = getClientLambda)
+        val migration = AppMigration09(sessionStore, clientProvider)
+        migration.migrate(isFreshInstall = false)
+
+        getClientLambda.assertions().isCalledOnce()
+        resetWellKnownLambda.assertions().isCalledOnce()
+    }
+}