Fix some concurrency warnings.

iOS/AppDefaults.swift

@@ -31,7 +31,7 @@ final class AppDefaults {
 
 	static let defaultThemeName = "Defaults"
 	
-	@MainActor static let shared = AppDefaults()
+	nonisolated(unsafe) static let shared = AppDefaults()
 	private init() {}
 	
 	static let store: UserDefaults = {

iOS/AppDelegate.swift

@@ -391,7 +391,9 @@ private extension AppDelegate {
 			do {
 				try BGTaskScheduler.shared.submit(request)
 			} catch {
-				os_log(.error, log: self.log, "Could not schedule app refresh: %@", error.localizedDescription)
+				Task { @MainActor in
+					os_log(.error, log: self.log, "Could not schedule app refresh: %@", error.localizedDescription)
+				}
 			}
 		}
 	}

iOS/Article/WebViewController.swift

@@ -17,7 +17,8 @@ import ArticleExtractor
 import Images
 
 protocol WebViewControllerDelegate: AnyObject {
-	func webViewController(_: WebViewController, articleExtractorButtonStateDidUpdate: ArticleExtractorButtonState)
+	
+	@MainActor func webViewController(_: WebViewController, articleExtractorButtonStateDidUpdate: ArticleExtractorButtonState)
 }
 
 final class WebViewController: UIViewController {