Implements swipe-back gesture support for mobile navigation across ChatView, MissionManager, and PlanningModeModal, wired through a shared navigation history context and covered by a comprehensive test suite (~548 lines of swipe-back tests). A small fixup ensures swipe-back behaves correctly when la
Fusion-Task-Id: FN-4139
Merged test(FN-3344): added comprehensive unit and integration tests for the navigation history hook, covering 470 lines of test coverage across navigation state management, history tracking, and edge cases.
Fusion-Task-Id: FN-3344
