Fix paywall close flow to allow reliable reopen.

Remove asynchronous overlay fade-out during close and tear down the paywall overlay immediately so subsequent open actions always present correctly.

Made-with: Cursor

classroom_app/ViewController.swift

@@ -1107,13 +1107,7 @@ private extension ViewController {
         if let overlay = paywallOverlayView {
             paywallOverlayView = nil
             paywallUpgradeFlowEnabled = false
-            NSAnimationContext.runAnimationGroup({ context in
-                context.duration = 0.16
-                context.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
-                overlay.animator().alphaValue = 0
-            }, completionHandler: {
-                overlay.removeFromSuperview()
-            })
+            overlay.removeFromSuperview()
             return
         }
         if let win = paywallWindow {
@@ -2837,8 +2831,8 @@ private extension ViewController {
         footer.widthAnchor.constraint(equalTo: contentStack.widthAnchor).isActive = true
 
         NSLayoutConstraint.activate([
-            closeButton.topAnchor.constraint(equalTo: panel.topAnchor, constant: 18),
-            closeButton.trailingAnchor.constraint(equalTo: panel.trailingAnchor, constant: -18),
+            closeButton.topAnchor.constraint(equalTo: panel.topAnchor, constant: 24),
+            closeButton.trailingAnchor.constraint(equalTo: panel.trailingAnchor, constant: -24),
             contentStack.centerXAnchor.constraint(equalTo: panel.centerXAnchor),
             contentStack.widthAnchor.constraint(equalToConstant: paywallLayoutWidth),
             contentStack.topAnchor.constraint(equalTo: panel.topAnchor, constant: 80),