- Backend: reject is_active=False users with HTTP 403 after password
verification but before session creation (prevents last_login_at
update, lockout reset, and MFA token issuance for disabled accounts)
- Frontend: optimistic setQueryData on successful login eliminates the
form flash between mutation success and auth query refetch
- LockScreen: replace lockoutMessage + toast.error with unified
loginError inline alert for 401/403/423 responses
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>