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

TraccarClientTests/WindowFocusTests.swift

@@ -0,0 +1,104 @@
+import Testing
+
+@MainActor
+struct WindowFocusTests {
+    @Test func restoresInitiatingWindowAfterActivationCompletes() async {
+        let activation = ActivationGate()
+        let window = FocusWindow()
+        let otherWindow = FocusWindow()
+        let focus = WindowFocusController { await activation.request() }
+        focus.window = window
+        var actionFinished = false
+        let task = focus.perform { actionFinished = true }
+        await activation.waitForRequest()
+        #expect(actionFinished && window.restorations == 0)
+        focus.window = otherWindow
+        activation.complete(success: true)
+        await task?.value
+        #expect(window.restorations == 1 && otherWindow.restorations == 0)
+    }
+
+    @Test(arguments: [false, true])
+    func closingOrMinimizingDuringActivationDoesNotRecoverWindow(minimized: Bool) async {
+        let activation = ActivationGate()
+        let window = FocusWindow()
+        let focus = WindowFocusController { await activation.request() }
+        focus.window = window
+        let task = focus.perform {}
+        await activation.waitForRequest()
+        if minimized { window.isMiniaturized = true } else { window.isVisible = false }
+        activation.complete(success: true)
+        await task?.value
+        #expect(window.restorations == 0)
+    }
+
+    @Test func missingOrClosedWindowDoesNotRequestActivation() async {
+        var requests = 0
+        let focus = WindowFocusController { requests += 1; return true }
+        #expect(focus.perform {} == nil)
+        let window = FocusWindow()
+        window.isVisible = false
+        focus.window = window
+        #expect(focus.perform {} == nil)
+        #expect(requests == 0)
+    }
+
+    @Test func activationFailureDoesNotOrderWindowForward() async {
+        let window = FocusWindow()
+        let focus = WindowFocusController { false }
+        focus.window = window
+        await focus.perform {}?.value
+        #expect(window.restorations == 0)
+    }
+
+    @Test func newerActionCancelsEarlierRestoration() async {
+        let activation = ActivationGate()
+        let window = FocusWindow()
+        var requests = 0
+        let focus = WindowFocusController {
+            requests += 1
+            if requests == 1 { return await activation.request() }
+            return true
+        }
+        focus.window = window
+        let first = focus.perform {}
+        await activation.waitForRequest()
+        await focus.perform {}?.value
+        #expect(window.restorations == 1)
+        activation.complete(success: true)
+        await first?.value
+        #expect(window.restorations == 1)
+    }
+}
+
+@MainActor
+private final class FocusWindow: FocusRestorationWindow {
+    var isVisible = true
+    var isMiniaturized = false
+    var restorations = 0
+    func restoreKeyWindow() { restorations += 1 }
+}
+
+@MainActor
+private final class ActivationGate {
+    private var completion: CheckedContinuation<Bool, Never>?
+    private var entered: CheckedContinuation<Void, Never>?
+
+    func request() async -> Bool {
+        await withCheckedContinuation { continuation in
+            completion = continuation
+            entered?.resume()
+            entered = nil
+        }
+    }
+
+    func waitForRequest() async {
+        if completion != nil { return }
+        await withCheckedContinuation { entered = $0 }
+    }
+
+    func complete(success: Bool) {
+        completion?.resume(returning: success)
+        completion = nil
+    }
+}