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
Previously the back button left the dashboard page entirely because
useNavigationHistory was only enabled for mobile viewports. Now it's
enabled for all viewports — desktop and mobile — so the browser back
button dismisses modals and reverts view changes within the SPA.
Changes:
- Enable useNavigationHistory for desktop (enabled: true instead of enabled: isMobile)
- Remove all isMobile ? historyAwareHandler : plainHandler ternaries
- Always use navigation-aware handlers (openDetailTask, openSettingsWithNav, etc.)
- Update JSDoc to reflect desktop support
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
