Fix Coolify deployment: use expose instead of ports

docker-compose.yml

@@ -1,8 +1,8 @@
 services:
   backend:
     build: ./backend
-    ports:
-      - "8000:8000"
+    expose:
+      - "8000"
     environment:
       - DATABASE_URL=sqlite+aiosqlite:///./data/h2h.db
       - JWT_SECRET=${JWT_SECRET:-your-secret-key-change-in-production-min-32-characters}
@@ -16,8 +16,8 @@ services:
 
   frontend:
     build: ./frontend
-    ports:
-      - "5173:5173"
+    expose:
+      - "5173"
     environment:
       - VITE_API_URL=http://localhost:8000
       - VITE_WS_URL=ws://localhost:8000