Private Chat MVP Build

I need a swift, stable MVP of a private chat application delivered in one week. The first release must focus on the essentials so I can validate core functionality before expanding.

Core scope
• One-to-one text chat with real-time updates
• Photo sharing inside the same chat stream (thumbnail preview and full-screen view)
• Access restricted to invited users only
• Secure email-and-password sign-in, including password reset flow

Technical expectations
Clean, well-structured code (React Native, Flutter, or another modern cross-platform stack) backed by a lightweight, scalable cloud database. Please include straightforward deployment scripts, environment samples, and README documentation so I can spin up staging and production instances without friction.

Security & stability
All traffic must travel over TLS, messages and images should be stored using secure, access-controlled buckets, and basic input sanitation is required to prevent common injection attacks.

Hand-off deliverables
1. Full source code in a private Git repository
2. Infrastructure / build scripts and .env templates
3. Clear setup & run instructions
4. Brief architecture overview outlining data flow and major components

After this milestone I plan to add voice messages, group chats, and push notifications, so designing with extensibility in mind is appreciated.