chore: add game server (Colyseus) - flat files

rolld_backend/game/src/index.js

@@ -0,0 +1,30 @@
+const cors = require('cors');
+const { Server } = require('@colyseus/core');
+const { WebSocketTransport } = require('@colyseus/ws-transport');
+const { ArenaRoom } = require('./rooms/ArenaRoom');
+
+const PORT = process.env.PORT || 2567;
+
+// Colyseus 0.17 – express callback receives the transport's internal Express app
+const gameServer = new Server({
+  transport: new WebSocketTransport(),
+  express: (app) => {
+    app.use(cors());
+
+    app.get('/health', (_req, res) => {
+      res.json({ service: 'game', status: 'ok', timestamp: new Date().toISOString() });
+    });
+
+    app.get('/', (_req, res) => {
+      res.send('🎮 Game server running');
+    });
+  },
+});
+
+// Define rooms
+gameServer.define('arena', ArenaRoom);
+console.log('✅ ArenaRoom registered');
+
+gameServer.listen(PORT).then(() => {
+  console.log(`🎮 Game server running on ws://localhost:${PORT}`);
+});