- API service (api.js): fetch wrapper with JWT, auto-refresh on 401
- AuthContext: user state, login/register/logout, loading, roles
- AuthModal: tabbed login/register form matching .pen design
- User badge in toolbar (Sandbox + WorldMap) with initial avatar
- "Entrar" button when not logged in
- CSS: auth overlay, card, tabs, inputs, error state, user badge
- Auth is opt-in: app works fully without login
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>