Fix environment updates propagation to children

Sources/TokamakCore/MountedViews/MountedHostView.swift

@@ -94,6 +94,7 @@ public final class MountedHostView<R: Renderer>: MountedElement<R> {
       while let child = mountedChildren.first, let firstChild = childrenViews.first {
         let newChild: MountedElement<R>
         if firstChild.typeConstructorName == mountedChildren[0].view.typeConstructorName {
+          child.environmentValues = environmentValues
           child.view = firstChild
           child.updateEnvironment()
           child.update(with: reconciler)

Sources/TokamakCore/Views/NavigationView.swift

@@ -30,7 +30,7 @@ public struct NavigationView<Content>: View where Content: View {
 }
 
 /// This is a helper class that works around absence of "package private" access control in Swift
-public struct _NavigationViewProxy<Content: View> {
+public struct _NavigationViewProxy<Content: View>: View {
   public let subject: NavigationView<Content>
 
   public init(_ subject: NavigationView<Content>) { self.subject = subject }

Sources/TokamakStaticHTML/Views/NavigationView.swift

@@ -22,7 +22,7 @@ extension NavigationView: ViewDeferredToRenderer {
       width: 100%; height: 100%;
       """,
     ]) {
-      _NavigationViewProxy(self).body
+      _NavigationViewProxy(self)
     })
   }
 }