feat(docker): add split backend/frontend stacks and dynamic versioning

deployment/docker/frontend/Dockerfile

@@ -0,0 +1,16 @@
+FROM nginx:alpine
+
+ARG APP_VERSION=1.1.9
+
+ENV APP_VERSION=${APP_VERSION}
+
+# Copy built frontend assets into nginx web root
+COPY src/frontend/dist /usr/share/nginx/html
+
+# Custom nginx config for SPA routing (serve index.html for unknown routes)
+COPY deployment/docker/frontend/nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80
+
+CMD ["nginx", "-g", "daemon off;"]
+