I am building a social-media application and I now need a robust instant-messaging feature added to the existing Android codebase. What I want right now • One-to-one and group chat with text, emoji, and basic file attachment support. • Real-time delivery and read indicators using a reliable service such as Firebase Cloud Messaging or a comparable solution. • Secure message storage (end-to-end or server-side encryption, depending on your recommended architecture). • Clean, Material-compliant UI components that slot naturally into my current screens. • Clear documentation so future updates—like photo/video sharing or push notifications—can be integrated smoothly. You should be comfortable refactoring Kotlin/Java code, setting up scalable back-end messaging (Firebase, Socket.IO, or a tech you propose), and handing over concise build instructions. A quick call to walk through the project structure and hand-off will be part of the final delivery.