improving build steps

OpenCand.UI.dockerfile

@@ -0,0 +1,26 @@
+# ─── Stage 1: Build ───────────────────────────────────────────────────────
+FROM node:slim AS builder
+WORKDIR /app
+
+COPY package.json yarn.lock ./
+RUN yarn install --frozen-lockfile
+
+COPY . .
+
+ARG VITE_API_BASE_URL
+ENV VITE_API_BASE_URL=${VITE_API_URL}
+
+RUN yarn build
+
+# ─── Stage 2: Serve ────────────────────────────────────────────────────────
+FROM nginx:stable-alpine
+# Remove default nginx html
+RUN rm -rf /usr/share/nginx/html/*
+# Copy our built files into nginx’s html folder
+COPY --from=builder /app/dist /usr/share/nginx/html
+
+# (Optional) If you need any custom nginx.conf, COPY it here—
+# e.g. COPY nginx.conf /etc/nginx/nginx.conf
+
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]