Add Docker configuration and environment setup for Tennis Roots project

server/Dockerfile

@@ -0,0 +1,15 @@
+# ---- Build ----
+FROM node:22-alpine AS builder
+WORKDIR /app
+COPY package.json package-lock.json ./
+RUN npm ci --omit=dev
+
+# ---- Run ----
+FROM node:22-alpine
+WORKDIR /app
+COPY --from=builder /app/node_modules ./node_modules
+COPY index.js ./
+
+EXPOSE 3000
+USER node
+CMD ["node", "index.js"]