KerimKochekov/Threejs-museum ? reverse-engineered prompt

Build me a simple browser game where you can walk around a virtual museum made with three.js.

I want it to feel like a small 3D museum you can explore in first person, with ghost mode so the player can move through walls and rooms freely. The main idea is that the museum has portraits or image frames on the walls, and those images can be changed or generated from whatever the user wants to see. Keep the experience smooth and playable, with basic lighting, a few rooms, and enough objects to make it feel like a real museum without getting too heavy.

Please make it run locally in the browser from an index page, and if you need to look up current three.js docs online, go ahead. Use the assets in the project if helpful, and keep the implementation clean enough that I can easily open it in a local server and start exploring right away.