feat: persist local configuration and device identity (#3)

Store receiver and identity together in Keychain, with versioned tracking
preferences, explicit authorization retry and stable Settings focus.
Adopt free Apple Development locally and credential-free ad hoc CI.
Run configuration and focus tests through both CI toolchains.

Final decisions: https://github.com/jayanezj/traccar-client-macos/issues/3#issuecomment-6396087703

TraccarClient/Application/TraccarClientApp.swift

@@ -5,6 +5,8 @@ import SwiftUI
 struct TraccarClientApp: App {
     @NSApplicationDelegateAdaptor(ApplicationDelegate.self) private var delegate
 
+    @State private var configuration = ConfigurationModel.live()
+
     var body: some Scene {
         MenuBarExtra {
             TrackingMenu()
@@ -16,13 +18,54 @@ struct TraccarClientApp: App {
         .menuBarExtraStyle(.menu)
 
         Settings {
-            SettingsView()
+            SettingsView(model: configuration)
         }
     }
 }
 
 @MainActor
 final class ApplicationDelegate: NSObject, NSApplicationDelegate {
+    private let openWindows = NSHashTable<NSWindow>.weakObjects()
+    private var closingWindows: Set<ObjectIdentifier> = []
+
+    func applicationDidFinishLaunching(_ notification: Notification) {
+        let center = NotificationCenter.default
+        let notifications = [
+            NSWindow.didBecomeKeyNotification, NSWindow.didUpdateNotification, NSWindow.willCloseNotification,
+        ]
+        for name in notifications {
+            center.addObserver(self, selector: #selector(windowChanged(_:)), name: name, object: nil)
+        }
+    }
+
+    @objc private func windowChanged(_ notification: Notification) {
+        guard let window = notification.object as? NSWindow,
+              window.level == .normal, window.canBecomeKey else { return }
+        let identity = ObjectIdentifier(window)
+        if notification.name == NSWindow.willCloseNotification {
+            closingWindows.insert(identity)
+            openWindows.remove(window)
+        } else {
+            if notification.name == NSWindow.didBecomeKeyNotification { closingWindows.remove(identity) }
+            guard !closingWindows.contains(identity), window.isVisible || window.isMiniaturized else { return }
+            openWindows.add(window)
+        }
+        let policy: NSApplication.ActivationPolicy = openWindows.allObjects.isEmpty ? .accessory : .regular
+        if NSApp.activationPolicy() != policy {
+            NSApp.setActivationPolicy(policy)
+            if policy == .regular { NSApp.activate() }
+        }
+    }
+
+    func applicationShouldHandleReopen(_ sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
+        guard WindowFocusController.pendingActivations == 0 else { return false }
+        if let window = sender.windows.first(where: { openWindows.contains($0) }) {
+            if window.isMiniaturized { window.deminiaturize(nil) }
+            window.makeKeyAndOrderFront(nil)
+        }
+        return false
+    }
+
     func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
         false
     }