Yep. AI rewrote the whole thing.

Downterm/CommandNotch/Models/AppSettingsController.swift

@@ -0,0 +1,74 @@
+import Foundation
+import Combine
+
+@MainActor
+final class AppSettingsController: ObservableObject, TerminalSessionConfigurationProviding {
+    static let shared = AppSettingsController(
+        store: UserDefaultsAppSettingsStore(),
+        observeExternalChanges: true
+    )
+
+    @Published private(set) var settings: AppSettings
+
+    private let store: any AppSettingsStoreType
+    private let notificationCenter: NotificationCenter
+    private var defaultsObserver: NSObjectProtocol?
+
+    init(
+        store: any AppSettingsStoreType,
+        observeExternalChanges: Bool = false,
+        notificationCenter: NotificationCenter = .default
+    ) {
+        self.store = store
+        self.notificationCenter = notificationCenter
+        self.settings = store.load()
+
+        if observeExternalChanges {
+            defaultsObserver = notificationCenter.addObserver(
+                forName: UserDefaults.didChangeNotification,
+                object: nil,
+                queue: .main
+            ) { [weak self] _ in
+                Task { @MainActor in
+                    self?.refresh()
+                }
+            }
+        }
+    }
+
+    deinit {
+        if let defaultsObserver {
+            notificationCenter.removeObserver(defaultsObserver)
+        }
+    }
+
+    var terminalSessionConfiguration: TerminalSessionConfiguration {
+        TerminalSessionConfiguration(
+            fontSize: CGFloat(settings.terminal.fontSize),
+            theme: settings.terminal.theme,
+            shellPath: settings.terminal.shellPath
+        )
+    }
+
+    var hotkeySettings: AppSettings.HotkeySettings {
+        settings.hotkeys
+    }
+
+    var terminalSizePresets: [TerminalSizePreset] {
+        settings.terminal.sizePresets
+    }
+
+    func refresh() {
+        let loaded = store.load()
+        guard loaded != settings else { return }
+        settings = loaded
+    }
+
+    func update(_ mutate: (inout AppSettings) -> Void) {
+        var updated = settings
+        mutate(&updated)
+        guard updated != settings else { return }
+        settings = updated
+        store.save(updated)
+    }
+}