add a process to clean up any expired messages before loading initial screen after app launch

Session/Meta/AppDelegate.swift

@@ -320,6 +320,11 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
         Configuration.performMainSetup()
         JobRunner.setExecutor(SyncPushTokensJob.self, for: .syncPushTokens)
         
+        /// We need to do a clean up for disappear after send messages that are received by push notifications before
+        /// the app set up the main screen and load initial data to prevent a case when the PagedDatabaseObserver
+        /// hasn't been setup yet then the conversation screen can show stale (ie. deleted) interactions incorrectly
+        DisappearingMessagesJob.cleanExpiredMessagesOnLaunch()
+        
         // Setup the UI if needed, then trigger any post-UI setup actions
         self.ensureRootViewController(calledFrom: lifecycleMethod) { [weak self] success in
             // If we didn't successfully ensure the rootViewController then don't continue as

SessionMessagingKit/Jobs/Types/DisappearingMessagesJob.swift

@@ -46,6 +46,24 @@ public enum DisappearingMessagesJob: JobExecutor {
     }
 }
 
+// MARK: - Clean expired messages on app launch
+
+public extension DisappearingMessagesJob {
+    static func cleanExpiredMessagesOnLaunch() {
+        let timestampNowMs: TimeInterval = TimeInterval(SnodeAPI.currentOffsetTimestampMs())
+        var numDeleted: Int = -1
+        
+        Storage.shared.write { db in
+            numDeleted = try Interaction
+                .filter(Interaction.Columns.expiresStartedAtMs != nil)
+                .filter((Interaction.Columns.expiresStartedAtMs + (Interaction.Columns.expiresInSeconds * 1000)) <= timestampNowMs)
+                .deleteAll(db)
+        }
+        
+        SNLog("[DisappearingMessagesJob] Deleted \(numDeleted) expired messages on app launch.")
+    }
+}
+
 // MARK: - Convenience
 
 public extension DisappearingMessagesJob {