Add Dockerfile, docker-compose and Makefile for container build

Dockerfile

@@ -0,0 +1,21 @@
+# ── Build stage ─────────────────────────────────────────────────────────────
+FROM docker.io/library/node:22-alpine AS build
+
+WORKDIR /app
+
+COPY web/package.json web/package-lock.json ./
+RUN npm ci
+
+COPY web/ ./
+RUN npm run build
+
+# ── Runtime stage ───────────────────────────────────────────────────────────
+FROM docker.io/library/nginx:1.27-alpine
+
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+COPY --from=build /app/dist /usr/share/nginx/html
+
+EXPOSE 80
+
+HEALTHCHECK --interval=30s --timeout=5s --retries=3 \
+  CMD wget -qO- http://localhost/ >/dev/null || exit 1