aljhassan/HexGPT ? reverse-engineered prompt

Build me a simple web app called HexGPT that lets someone type a plain English prompt and get back a matching color palette. I want the experience to feel easy and friendly, with a clean chat style input where a user can describe a mood, theme, brand, or scene, then see a set of colors generated from that description.

The app should use an OpenAI API key from the environment, and if the key is missing it should clearly tell the user what they need to do. Show the palette in a polished way with the hex codes visible and easy to copy, and make the results feel quick and modern. Please keep the design responsive so it works well on desktop and mobile.

If you need to, look up the current SvelteKit or deployment docs online to make sure the project runs and builds properly. I also want the app to be ready for a simple production deploy, with a good default setup for previewing and building locally.