Fix: Incorrect Role-Based Redirection and Stale Auth Session

Summary

A bug was identified where users with different roles (e.g., Volunteers) were incorrectly redirected to Admin-only pages after a previous Admin session had ended. This occurred because the application was using stale session state and lacked strict role-based authorization checks in the routing layer.

Root Causes

• Stale User State: The logout function in AuthContext.tsx cleared the authentication token but did not explicitly reset the user state. This allowed the application to briefly perceive a new user as having the previous user's role or destination.
• Missing Authorization: The ProtectedRoute component only checked for isAuthenticated but did not verify if the authenticated user possessed the required role for a specific route.
• Redirection Logic: The LoginPage would redirect to the from location stored in the router state (e.g., an admin page), which the ProtectedRoute failed to block for non-admin users.

Proposed Changes

• Clear State on Logout: Update AuthContext.tsx to set user to null immediately upon logout.
• Enhance ProtectedRoute: Update ProtectedRoute.tsx to accept an allowedRoles prop and verify user roles before granting access.
• Guard Admin Routes: Update App.tsx to enforce the admin role for all routes starting with /admin/.
• Test Alignment: Update unit tests to reflect the current UI labels and ensure all 1312 tests pass.

Verification

• Unit Tests: Ran npm run test:run. All 1312 tests passed, including authentication and registration flows.
• Manual Flow: Verified that logging out as an Admin and in as a Volunteer no longer results in an incorrect redirect to admin pages.