chore: add Dockerfile for deployment

.dockerignore

@@ -0,0 +1,6 @@
+node_modules
+data
+.env
+.git
+docs
+test

Dockerfile

@@ -0,0 +1,14 @@
+FROM node:22-slim AS build
+RUN apt-get update && apt-get install -y --no-install-recommends python3 build-essential \
+    && rm -rf /var/lib/apt/lists/*
+WORKDIR /app
+COPY package.json package-lock.json ./
+RUN npm ci --omit=dev
+COPY . .
+
+FROM node:22-slim
+WORKDIR /app
+COPY --from=build /app .
+ENV NODE_ENV=production
+EXPOSE 3000
+CMD ["node", "server.js"]