feat: first tries at save dialog, so far failing

MLXServer/Utilities/FocusedValues.swift

@@ -0,0 +1,13 @@
+import SwiftUI
+
+/// Focused value key for triggering chat export from the menu bar.
+struct FocusedExportTriggerKey: FocusedValueKey {
+    typealias Value = Binding<Bool>
+}
+
+extension FocusedValues {
+    var exportTrigger: Binding<Bool>? {
+        get { self[FocusedExportTriggerKey.self] }
+        set { self[FocusedExportTriggerKey.self] = newValue }
+    }
+}