Converting Single Tenant to Multi-Tenant CRM

About the project I run a wedding business and have built a full-featured wedding CRM (live at cinchedcrm.com, built on Replit using Claude to code). It currently runs as a single business. I want to turn it into a multi-tenant SaaS I can sell to other wedding vendors on monthly subscriptions. The app is already complete on features - this job is the SaaS foundation and going-to-market plumbing, not building the app from scratch. Scope of work Multi-tenancy with strict data isolation. I plan to use Supabase (Postgres + Row Level Security) so each account only ever sees its own data. Add an org/account model and org_id on all tables, with RLS enforced everywhere. Migrate existing data in as the first tenant. Auth via Supabase Auth (email/password, password reset, Google sign-in). Self-serve sign-up + onboarding - each signup creates its own workspace with a setup wizard. Stripe subscription billing - tiered plans + free trial, upgrade/downgrade/cancel, webhooks, plan/seat feature-gating, dunning for failed payments. Per-account white-label branding (logo/colors) across proposals, contracts, invoices, portal, and emails. Roles & seats (owner/admin/coordinator). A public marketing/landing + pricing page. (we can handle building this - if needed) Google OAuth production verification for Gmail + Calendar - OR integrate a pre-verified aggregator (e.g., Nylas/Unipile) to avoid the CASA restricted-scope assessment. Advise on the best approach. Move the codebase to a private GitHub repo and (as part of this work) off Replit-managed services to production hosting with automated backups and monitoring. Security & production readiness - secure secrets, tested isolation, backups, error monitoring. This can turn into a long term monthly management after the initial build.