Replaces hardcoded \"https://yourapp.com\" with a Spring property. - application.yml: app.base-url defaults to http://localhost:5173 - application-docker.yml: reads APP_BASE_URL env var, same default - HouseholdService: injects @Value("${app.base-url}") and uses it in toInviteResponse() to build shareUrl - HouseholdServiceTest: sets field via ReflectionTestUtils in @BeforeEach; adds test asserting shareUrl starts with configured base URL Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>