feat(real-estate): complete admin workflow integration and client api parity

feat(investment): seed + purge test-data commands + DATE_FORMAT SQLite fix

Backend: Essentials, Investment Club foundation + NAV engine, vehicle CRUD,

feat(calendly): shared Calendly API client + real advisory-meeting booking on Applications

feat(products): merge missing Products domain from mdn-backend main into migration branch

feat(membership): admin-driven account creation, real estate tier/investment work, in-progress monorepo migration state