Reduce Docker build memory use on small VPS

Dockerfile

@@ -18,12 +18,12 @@ ENV NODE_ENV=production \
 RUN if [ -z "$NEXT_PUBLIC_SUPABASE_URL" ] || [ -z "$NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY" ]; then \
       echo "In Dokploy, set NEXT_PUBLIC_SUPABASE_URL and NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY under Application > Environment > Build Time Arguments." >&2; \
       exit 1; \
-    fi && npm run build
+    fi && npm run build:docker
 
-FROM node:22-bookworm-slim AS production-dependencies
-WORKDIR /app
-COPY package.json package-lock.json ./
-RUN npm ci --omit=dev --no-audit --no-fund
+# Reuse the installation, and prune only after the build has completed.
+# A second independent npm ci stage could overlap with compilation in BuildKit.
+FROM builder AS production-dependencies
+RUN npm prune --omit=dev --no-audit --no-fund
 
 FROM node:22-bookworm-slim AS runner
 WORKDIR /app