Update dockerfiles

Author: chrissearle

backend/Dockerfile

@@ -1,7 +1,10 @@
-FROM eclipse-temurin:22 AS build
+# syntax=docker/dockerfile:1.20
+
+FROM --platform=$BUILDPLATFORM eclipse-temurin:22 AS build
 
 WORKDIR /build
 COPY . .
+
 RUN ./gradlew clean build
 
 FROM eclipse-temurin:22-jre AS deploy

frontend/Dockerfile

@@ -1,11 +1,14 @@
-FROM node:22-alpine AS build
+# syntax=docker/dockerfile:1.20
+
+FROM --platform=$BUILDPLATFORM node:24-alpine AS build
 
 WORKDIR /app
 COPY . .
-RUN npm install
+
+RUN npm ci
 RUN npm run build
 
-FROM node:22-alpine AS deploy
+FROM node:24-alpine AS deploy
 
 WORKDIR /app
 COPY --from=build /app/.output/ /app