Implemented global 401 response handling to properly redirect users
to login when their session expires:
Changes:
frontend/src/api/client.ts: Added setAuthErrorHandler() callback
pattern and enhanced 401 interceptor to notify auth context
frontend/src/context/AuthContext.tsx: Register auth error handler
that clears state and redirects to /login on 401 responses
tests/core/authentication.spec.ts: Fixed test to clear correct
localStorage key (charon_auth_token)
The implementation uses a callback pattern to avoid circular
dependencies while keeping auth state management centralized.
Auth endpoints (/auth/login, /auth/me) are excluded from the
redirect to prevent loops during initial auth checks.
All 16 authentication E2E tests now pass including:
should redirect to login when session expires
should handle 401 response gracefully
Closes frontend-auth-guard-reload.md
85802a75fc