Docker Compose & Local Dev Setup for HomeOrganizer

[kranthi2324]

Provide a reliable, documented Docker Compose setup to run all services for local development:

• Build containers for backend (Express), AI microservice (FastAPI), and frontend (React/nginx).
• Volume mounts for uploads and source code, ports exposed as: backend (4000), ai (8002), frontend (3000).
• Production-ready nginx config for frontend (proxies /api to backend in container network).
• Documentation for quickstart, troubleshooting, port changes, and data persistence.
• .env.example to make local overrides easy.

Acceptance:

• A single docker compose up --build brings up all services and persists uploads/data.
• README includes demo and troubleshooting instructions.
• Adaptable for future service addition (queue, S3, Postgres, etc.).