Feat: Hybrid Architecture Phase 1

- Implemented Game Server (game-server.js) with Socket.io
- Added JSON Schemas for Campaigns and Missions
- Updated Docker configurations for multi-service setup
- Refactored main.js to allow local network connections
- Removed legacy code (main_old.js)
- Updated dependencies

docker-compose.yml

@@ -8,3 +8,13 @@ services:
       - /app/node_modules
     environment:
       - CHOKIDAR_USEPOLLING=true
+    command: npm run dev
+
+  server:
+    build: .
+    ports:
+      - "3001:3001"
+    volumes:
+      - .:/app
+      - /app/node_modules
+    command: node game-server.js