✨(frontend) build specialized DINUM image from generic frontend

Create DINUM-specific frontend build from generic white-label base to
validate recent white-labeling work. Sources will eventually be extracted
to separate repo and pulled as submodule.

docker/dinum-frontend/Dockerfile

@@ -0,0 +1,56 @@
+# ---- Front-end image ----
+FROM node:20-alpine AS frontend-deps
+
+WORKDIR /home/frontend/
+
+COPY ./src/frontend/package.json ./package.json
+COPY ./src/frontend/package-lock.json ./package-lock.json
+
+RUN npm ci
+
+COPY .dockerignore ./.dockerignore
+COPY ./src/frontend/ .
+
+### ---- Front-end builder image ----
+FROM frontend-deps AS meet-builder
+
+WORKDIR /home/frontend
+
+ENV VITE_APP_TITLE="Visio"
+
+RUN npm run build
+
+COPY ./docker/dinum-frontend/dinum-styles.css \
+    ./dist/assets/
+
+COPY ./docker/dinum-frontend/logo.svg \
+    ./dist/assets/logo.svg
+
+COPY ./docker/dinum-frontend/assets/ \
+    ./dist/assets/
+
+COPY ./docker/dinum-frontend/fonts/ \
+    ./dist/assets/fonts/
+
+# ---- Front-end image ----
+FROM nginxinc/nginx-unprivileged:alpine3.21 AS frontend-production
+
+USER root
+RUN apk update && apk upgrade libssl3 libcrypto3 libxml2>=2.12.7-r2 libxslt>=1.1.39-r2
+
+USER nginx
+
+# Un-privileged user running the application
+ARG DOCKER_USER
+USER ${DOCKER_USER}
+
+COPY --from=meet-builder \
+    /home/frontend/dist \
+    /usr/share/nginx/html
+
+COPY ./src/frontend/default.conf /etc/nginx/conf.d
+COPY ./docker/files/usr/local/bin/entrypoint /usr/local/bin/entrypoint
+
+ENTRYPOINT [ "/usr/local/bin/entrypoint" ]
+
+CMD ["nginx", "-g", "daemon off;"]