Add a new AccountSettings type and compose it with AppSettings into UserSettings.

The new type doesn't contain any settings yet.

ElementX/Sources/Application/Settings/UserSettings.swift

@@ -0,0 +1,49 @@
+//
+// Copyright 2026 Element Creations Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+// Please see LICENSE files in the repository root for full details.
+//
+
+import Foundation
+
+/// The settings for a signed in account, composed of the app wide settings and the settings
+/// specific to that account.
+@dynamicMemberLookup
+final nonisolated class UserSettings: Sendable {
+    let app: AppSettings
+    let account: AccountSettings
+    
+    init(appSettings: AppSettings, accountSettings: AccountSettings) {
+        self.app = appSettings
+        self.account = accountSettings
+    }
+    
+    static func volatile() -> UserSettings {
+        let appSettings = AppSettings.volatile()
+        return UserSettings(appSettings: appSettings, accountSettings: .init())
+    }
+    
+    subscript<Value>(dynamicMember keyPath: ReferenceWritableKeyPath<AppSettings, Value>) -> Value {
+        get { app[keyPath: keyPath] }
+        set { app[keyPath: keyPath] = newValue }
+    }
+    
+    subscript<Value>(dynamicMember keyPath: KeyPath<AppSettings, Value>) -> Value {
+        app[keyPath: keyPath]
+    }
+    
+    subscript<Value>(dynamicMember keyPath: ReferenceWritableKeyPath<AccountSettings, Value>) -> Value {
+        get { account[keyPath: keyPath] }
+        set { account[keyPath: keyPath] = newValue }
+    }
+    
+    subscript<Value>(dynamicMember keyPath: KeyPath<AccountSettings, Value>) -> Value {
+        account[keyPath: keyPath]
+    }
+}
+
+/// Settings specific to an account.
+struct AccountSettings {
+    // Placeholder for now, implementation to follow with a dedicated user defaults store scoped to a specific user ID.
+}