Fixes problems around holding on to the YubiKey when in background

Author: jdmoreira

Authenticator/Model/MainViewModel.swift

@@ -109,6 +109,8 @@ class MainViewModel: ObservableObject {
                         self?.isKeyPluggedIn = false
                         self?.sessionError = error
                     }
+                    // exit if cancelled
+                    guard !Task.isCancelled else { return }
                 }
             } catch {
                 if let sessionError = error as? OATHSessionError {
@@ -137,6 +139,9 @@ class MainViewModel: ObservableObject {
         isKeyPluggedIn = false
         sessionError = nil
         connectionError = nil
+
+        OATHSessionHandler.shared.smartCardConnection?.stop()
+        OATHSessionHandler.shared.accessoryConnection?.stop()
     }
 
     @MainActor private func updateAccount(_ account: Account) async {

Authenticator/Model/OATHSession.swift

@@ -48,9 +48,9 @@ class OATHSessionHandler: NSObject, YKFManagerDelegate {
 
     typealias ClosingCallback = ((_ error: Error?) -> Void)
 
-    private var nfcConnection: YKFNFCConnection?
-    private var smartCardConnection: YKFSmartCardConnection?
-    private var accessoryConnection: YKFAccessoryConnection?
+    var nfcConnection: YKFNFCConnection?
+    var smartCardConnection: YKFSmartCardConnection?
+    var accessoryConnection: YKFAccessoryConnection?
 
     private var currentSession: YKFOATHSession?