Split the site out, and offer the source the licence requires

The hub page and the games.jcoffey.dev deployment move to their own
private repository; this one keeps only the game, its leaderboard and a
generic compose that runs both anywhere. No deployment details remain
here, and no site references.

A SOURCE link now sits on every screen. AGPL section 13 entitles anyone
playing this over a network to the source of what they are playing, and
a link in the footer is how that offer gets made.

vite.config.ts

@@ -3,8 +3,8 @@ import { defineConfig } from 'vite'
 
 // https://vite.dev/config/
 export default defineConfig({
-  // The game is served under a path on games.jcoffey.dev, so asset URLs have
-  // to be built for it. Local development stays at the root.
+  // Asset URLs are baked in at build time, so this has to match the path the
+  // game is served from. Local development stays at the root.
   base: process.env.BASE_PATH ?? '/',
   plugins: [react()],
   server: {