completed iOS push notification setup: created the NotificationServiceExtension Xcode target programmatically (via xcodeproj), embedded it in Runner, and added its xcconfig base configs; fixed Automatic Signing by switching the NSE↔Runner shared keychain from an app-group to a team-prefixed access group across entitlements, Dart and Swift; fixed the analyzer break from dio 5.9.2 dropping DioExceptionType.transformTimeout

ios/Runner/AppDelegate.swift

@@ -12,7 +12,7 @@ import UserNotifications
   private let markReadActionId = "TALK_MARK_READ"
 
   // Shared (App Group) keychain — same group as the NSE and the Dart side.
-  private let keychainAccessGroup = "group.eu.mhsl.marianum.mobile.client.widget"
+  private let keychainAccessGroup = "MY55VF3KPG.eu.mhsl.marianum.mobile.client.push"
   private let usernameAccount = "nextcloud_username"
   private let appPasswordAccount = "nextcloud_app_password"
   private let baseUrlAccount = "nextcloud_base_url"

ios/Runner/Runner.entitlements

@@ -11,7 +11,7 @@
 	</array>
 	<key>keychain-access-groups</key>
 	<array>
-		<string>group.eu.mhsl.marianum.mobile.client.widget</string>
+		<string>$(AppIdentifierPrefix)eu.mhsl.marianum.mobile.client.push</string>
 	</array>
 </dict>
 </plist>