Site admins can now temporarily view the site as a player, tournament admin,
or club admin to understand the experience for each role.
Changes:
- Added RoleSwitcher context and provider for client-side role simulation
- Added role switcher dropdown in Navigation (visible only to site admins)
- Added yellow banner showing current viewing-as role with reset button
- Navigation links and wordmark href now use effective role for conditional display
- Added BDD feature file with 5 scenarios covering all role transitions
- Added step definitions for site admin login and role switcher interactions
The view-as feature is purely UI-level - server-side permissions remain unchanged.
5 scenarios, 27 steps, all passing.
