Integrate Database, API & Front-ends

I have three separate pieces of software that must start talking to each other as a single product for a certain use case:

• a MySQL (or compatible) database that already stores the source data
• a collection of PHP REST endpoints that expose that data
• two client applications—one in React for web, other in PHP, LLMs, and a few other technologies. It's a multi-tenant design

Right now each part works in isolation. I need the whole stack plugged together so that any change originating from one side instantly propagates everywhere else (think socket-driven or similar real-time updates).

What I expect from you
1. Tighten up the PHP backend: expand or refactor the existing API so it cleanly serves both Flutter and React, handles authentication, and broadcasts real-time events.
2. Wire the clients: adjust state-management in the Flutter app and the React dashboard so they subscribe to those events and refresh views without manual reloads.
3. Set up the data layer: ensure database reads/writes remain atomic, efficient, and secure while supporting the live-update mechanism.
4. Deliver code, migration scripts, and a brief README that lets me spin the whole environment up locally (docker-compose is fine) and on production.

Acceptance criteria
• Creating, updating, or deleting a record from either client reflects on the other client within two seconds.
• No hard-coded URLs, tokens, or credentials anywhere in the repos.
• API test suite (Postman collection or PHPUnit) proves all endpoints work.

If this matches your skill set in PHP, Flutter, React, WebSockets (or an equivalent push technology), let’s get started.