Schem-at/schematic-renderer ? reverse-engineered prompt

Build me a browser based 3D viewer for Minecraft schematics that can load .schematic, .schem, .litematic, and resource pack zip files.

I want to be able to drag and drop files onto the page, see the schematic rendered in a nice interactive canvas, and move around with orbit, fly, and first person style controls. It should feel fast, handle big builds well, and show loading progress while it works. Please include a simple sidebar for settings like grid, axes, camera mode, lighting, and rendering quality, plus a few keyboard shortcuts that are easy to change.

If it makes sense, use modern web rendering and current docs online for anything you need to check. Also make sure it can run in the browser as a single easy to use package, with the heavy work happening in the background so the UI stays smooth.