improvement: fixed some package.json issues. readme files updated.

frontend/Dockerfile

@@ -1,5 +1,5 @@
 # Build stage — produces `.next/standalone` (see next.config.ts output: standalone)
-FROM node:18-alpine AS builder
+FROM node:20-alpine AS builder
 
 WORKDIR /app
 
@@ -21,7 +21,7 @@ ENV NEXT_PUBLIC_APP_NAME=${NEXT_PUBLIC_APP_NAME}
 RUN npm run build
 
 # Production — minimal runtime using Next.js standalone bundle
-FROM node:18-alpine AS runner
+FROM node:20-alpine AS runner
 
 RUN apk add --no-cache dumb-init