Don't require DuckableContainer to manage navigation controller

Packages/ComposeUI/Sources/ComposeUI/Controllers/ComposeController.swift

@@ -244,6 +244,13 @@ public final class ComposeController: ViewController {
         }
         
         var body: some View {
+            NavigationView {
+                navRoot
+            }
+            .navigationViewStyle(.stack)
+        }
+        
+        private var navRoot: some View {
             ZStack(alignment: .top) {
                 // just using .background doesn't work; for some reason it gets inset immediately after the software keyboard is dismissed
                 config.backgroundColor
@@ -291,6 +298,7 @@ public final class ComposeController: ViewController {
             })
             .onDisappear(perform: controller.onDisappear)
             .navigationTitle(controller.navigationTitle)
+            .navigationBarTitleDisplayMode(.inline)
         }
         
         private var mainList: some View {

Packages/Duckable/Sources/Duckable/DuckAnimationController.swift

@@ -63,6 +63,9 @@ class DuckAnimationController: NSObject, UIViewControllerAnimatedTransitioning {
             let fadeAnimator = UIViewPropertyAnimator(duration: 0.1, curve: .linear) {
                 presented.view.layer.opacity = 0
             }
+            fadeAnimator.addCompletion { _ in
+                presented.view.layer.opacity = 1
+            }
             fadeAnimator.startAnimation(afterDelay: 0.3)
 
         } else {
@@ -80,6 +83,7 @@ class DuckAnimationController: NSObject, UIViewControllerAnimatedTransitioning {
                 presented.view.layer.opacity = 0
             }
             fadeAnimator.addCompletion { _ in
+                presented.view.layer.opacity = 1
                 duckable.duckableViewControllerDidFinishAnimatingDuck()
                 transitionContext.completeTransition(true)
             }

Packages/Duckable/Sources/Duckable/DuckableContainerViewController.swift

@@ -88,10 +88,9 @@ public class DuckableContainerViewController: UIViewController, DuckableViewCont
     
     private func doPresentDuckable(_ viewController: DuckableViewController, animated: Bool, completion: (() -> Void)?) {
         viewController.duckableDelegate = self
-        let nav = UINavigationController(rootViewController: viewController)
-        nav.modalPresentationStyle = .custom
-        nav.transitioningDelegate = self
-        present(nav, animated: animated) {
+        viewController.modalPresentationStyle = .custom
+        viewController.transitioningDelegate = self
+        present(viewController, animated: animated) {
             self.configureChildForDuckedPlaceholder()
             completion?()
         }