update for latest Node v26

Dockerfile

@@ -1,11 +1,11 @@
-FROM node:25 AS builder
+FROM node:26 AS builder
 ADD frontend/package*.json /app/
 WORKDIR /app
 RUN npm install
 ADD frontend /app
 RUN npm run build
 
-FROM node:25
+FROM node:26
 ADD backend/package*.json /app/
 WORKDIR /app
 RUN npm install