chore: add deployment and environment configuration files

Add .env.example for environment variable reference, nixpacks.toml for Nixpacks deployment, and docker-compose.yml for containerized deployment. These files provide necessary configuration for running the application in different environments.

nixpacks.toml

@@ -0,0 +1,11 @@
+[phases.setup]
+nixPkgs = ["nodejs", "python3", "gcc", "gnumake"]
+
+[phases.install]
+cmds = ["npm install"]
+
+[phases.build]
+cmds = ["mkdir -p data"]
+
+[start]
+cmd = "npm run seed && npm start"