VPN-7317: Fix XPC connection use-after-free after sign-out (#10823) (#10824)

Co-authored-by: Naomi Kirby <[email protected]>

Author: mcleinman

src/platforms/macos/macoscontroller.mm

@@ -47,7 +47,9 @@ - (id)initWithObject:(ControllerImpl*)controller;
 
 MacOSController::~MacOSController() {
   if (m_connection != nil) {
-    [static_cast<NSXPCConnection*>(m_connection) release];
+    NSXPCConnection* conn = static_cast<NSXPCConnection*>(m_connection);
+    [conn invalidate];
+    [conn release];
   }
 }
 
@@ -222,6 +224,9 @@ - (id)initWithObject:(ControllerImpl*)controller;
     QJsonObject jsObj = QJsonDocument::fromJson(jsBlob).object();
     emit initialized(true, jsObj.value("connected").toBool(),
                      QDateTime::fromString(jsObj.value("date").toString()));
+    
+    // The delegate is now owned by the NSXPCConnection
+    [delegate release];
   }];
 }