feat(gui): Rename Context Hub to Project Settings

- gui_2.py: Window title changed to 'Project Settings'
- app_controller.py: show_windows key updated
- Updated tests to reference new name

tests/test_gui2_layout.py

@@ -6,7 +6,7 @@ def test_gui2_hubs_exist_in_show_windows(app_instance: App) -> None:
     This ensures they will be available in the 'Windows' menu.
     """
  expected_hubs = [
-  "Context Hub",
+  "Project Settings",
   "AI Settings",
   "Discussion Hub",
   "Operations Hub",