Add docker build file for UI and associated Actions workflow

barkmanui/release.Dockerfile

@@ -0,0 +1,17 @@
+# Stage 1: Build Image
+FROM node:22-alpine AS build
+WORKDIR /app
+COPY package*.json ./
+RUN npm install
+COPY . .
+RUN npm run build -- --mode docker
+
+# Stage 2, use the compiled app, ready for production with caddy
+FROM caddy:latest
+COPY ops/docker/caddy/Caddyfile /etc/caddy/Caddyfile
+COPY --from=build /app/dist /app
+COPY ops/docker/entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+EXPOSE 80
+
+ENTRYPOINT ["/bin/sh", "/entrypoint.sh"]