Vton demo

[kailashahirwar]

Add Full-Stack Virtual Try-On Demo with FastAPI Backend

Overview
Introduces a production-ready virtual try-on web application with Next.js frontend and FastAPI backend, supporting 4 AI models (Nano Banana, Nano Banana Pro, FLUX 2 Pro, FLUX 2 Flex).

Key Changes

1. Frontend: Modern Next.js 15 app with drag & drop image upload, real-time cost estimation, and responsive design (demo/virtual-tryon/)
2. Backend: FastAPI server (api_server.py) with RESTful API, multi-model support, and comprehensive error handling
3. API Endpoint: POST /api/v1/virtual-tryon for generating virtual try-on images with multiple garment support
4. Dependencies: Added fastapi==0.124.0, uvicorn==0.38.0, python-multipart==0.0.20

Usage
python api_server.py # Start backend on :8000
cd demo/virtual-tryon && npm install && npm run dev # Start frontend on :3000

Documentation
Complete documentation added in demo/virtual-tryon/README.md, and Documentation (docs/docs/demos/virtual-tryon.md). Updated main README.md with demo section.