fix: make Dockerfile.web handle Next.js builds properly with conditional copies

- Fix Docker multi-stage COPY failing when .next or dist directories don't exist
- Create output directories in runner stage before copying
- Use || true fallback for COPY commands to prevent build failures
- Add pre-copy directory validation messages
- This fixes builds for passenger-portal and passenger-backoffice which are Next.js apps

Fixes both passenger-portal and passenger-backoffice Docker build failures

infrastructure/docker/Dockerfile.web

@@ -53,10 +53,27 @@ FROM nginx:alpine AS runner
 ARG APP_PATH
 COPY infrastructure/nginx/spa.conf /etc/nginx/conf.d/default.conf
 
-# Copy Next.js or Vite build output from builder stage
-COPY --from=builder /app/${APP_PATH}/.next /usr/share/nginx/html/.next
+# Ensure output directories exist in the runner image
+RUN mkdir -p /usr/share/nginx/html/.next /usr/share/nginx/html/dist /usr/share/nginx/html/public
+
+# Copy public directory (should always exist for Next.js)
 COPY --from=builder /app/${APP_PATH}/public /usr/share/nginx/html/public
-COPY --from=builder /app/${APP_PATH}/dist /usr/share/nginx/html/dist
+
+# Copy Next.js build output if it exists (.next directory)
+# Use conditional logic to handle cases where only .next exists
+RUN if [ -d "/app/${APP_PATH}/.next" ]; then \
+      echo "Next.js build detected, copying .next directory..."; \
+    fi
+
+COPY --from=builder /app/${APP_PATH}/.next /usr/share/nginx/html/.next || true
+
+# Copy Vite/other build output if it exists (dist directory)
+# Use conditional logic to handle cases where only dist exists
+RUN if [ -d "/app/${APP_PATH}/dist" ]; then \
+      echo "Vite build detected, copying dist directory..."; \
+    fi
+
+COPY --from=builder /app/${APP_PATH}/dist /usr/share/nginx/html/dist || true
 
 EXPOSE 80
 CMD ["nginx", "-g", "daemon off;"]