BrainoOS Web-Based Operating System

I am building BrainoOS, a browser-accessible operating system that behaves much like a traditional desktop environment yet lives entirely online. The core milestone is a functional prototype where users can sign in and instantly find themselves in a self-contained workspace for web development—think code editor, console, and live preview running inside the OS window system.

Key goals I need tackled:
• A modular desktop-style interface rendered in the browser (React, Vue, or similar front-end frameworks are fine as long as the result is smooth and responsive).
• Secure user sessions with persistent storage so projects and personal settings survive a logout.
• Integrated web-development tools: file manager, syntax-highlighting editor, and an embedded terminal that can run typical build commands (npm, yarn, etc.).
• Room for growth: the architecture must allow me to drop in extra “apps” later—whether that is a notes utility, media player, or anything else.

In your proposal, walk me through:
1. The tech stack you recommend and why it fits a cloud OS.
2. How you will structure the front end, back end, and real-time communication layer.
3. A milestone plan from initial prototype to first public beta, including the testing approach.
4. Any comparable work you have shipped and what you learned from it.

Only well-thought-out, detailed project proposals will be considered—please skip copy-paste replies. Once we agree on scope, I will share design sketches and the current repository so you can hit the ground running.