Heatcheck — FACEIT CS2 Stats by Angelok

Full source code: https://github.com/Angelokkus/heatcheck
The package is bundled with esbuild + TypeScript.
Build (Node.js 20+): 1) npm install 2) npm run build → the Firefox package is the contents of dist/firefox.

How to test:
The extension needs a free FACEIT Data API key.
1) Get a key at https://developers.faceit.com (create an app → Server-Side API key).
2) Open the extension popup → "API & Cache" → paste the key → Save.
3) Open any FACEIT CS2 match room (https://www.faceit.com/en/cs2/room/<id>) — stat badges and a panel appear under each player.
I can provide a ready test key on request at angelokkus@gmail.com.