Remove duplicated private authenticateInSession from AuthController and
HouseholdController. Add a single public implementation on AuthService
with session fixation protection built in. HouseholdController now
injects AuthService and passes role "user" for invite-accepted accounts.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Each domain had a single-implementation interface (e.g. AdminService
interface + AdminServiceImpl). Merged implementation into the service
class and deleted the redundant interfaces per KISS principle.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>