fix(ios/engine): engine migration must precede installs

ios/engine/KMEI/KeymanEngine/Classes/Resource Management/ResourceFileManager.swift

@@ -328,6 +328,18 @@ public class ResourceFileManager {
       throw KMPError.resourceNotInPackage
     }
 
+    /**
+     * A surprisingly critical line.  The Manager.shared instance must be initialized at some
+     * point before the resources are _actually_ stored and reigstered.  Otherwise, the initial
+     * Migrations pass (called early in Manager.init) will interpret the installation as from a
+     * different engine version and will break anything installed before it's run.
+     *
+     * Fortunately... all 14.0's installation methods pass through this single method in order to
+     * do the actual "storing" and "registering".  So, it's a decent-enough place to force
+     * Manager.shared's init.
+     */
+    _ = Manager.shared
+
     do {
       try copyWithOverwrite(from: package.sourceFolder,
                             to: Storage.active.packageDir(for: package)!)

ios/samples/KMSample2/KMSample2/AppDelegate.swift

@@ -20,6 +20,8 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
     KeymanEngine.log.logAppDetails()
 
     // Replace with your application group id
+    // Ensure this happens before installing any keyboards or models within the engine
+    // whenever using App Group Identifiers.
     Manager.applicationGroupIdentifier = "group.KMSample"
     return true
   }