Add Subscriptions, Accounts, Database and Security to Website

I need help adding subscriptions using Stripe, user accounts, security features, and a database to my website. The work includes setting up recurring payments, creating user registration and login, protecting sensitive areas and preventing website cloning, storing user and transaction data securely. I’m looking for someone who can build a reliable system, improve site security, and ensure everything works smoothly after launch. Prevent the page or any of its features from being cloned, as well as prevent the display of sensitive code I need the user's projects to be stored in a database; each user has a certain number of projects they can save, linked to their subscription Depending on their subscription level, I need the user to be able to access a limited number of features Payments must be processed through Stripe. Upon project completion, the Stripe account and databases must be linked to our accounts. Pricing and feature restrictions must be modifiable after development is complete. Actual State: Web application (SPA) for creating digital and analog signals. Stack: React 18 + TypeScript + Vite 6, styling with Tailwind CSS v4, Everything runs on the client side: no backend, persistence in localStorage, custom ES/EN i18n, and light/dark themes using CSS variables. No router, global state manager, tests, or linter configured. Website link https://digitalsignalcreator.netlify.app/ (currently only contains placeholders for the required functions)