Bump Docker Node images to 22.23.4 for October 2026 security fixes.

Node 20 is not in the patched release line; 22.23.4 addresses the high-severity TLS, DNS, and Brotli issues from the Node.js security release.

backend/Dockerfile.dev

@@ -1,4 +1,4 @@
-FROM node:20-alpine
+FROM node:22.23.4-alpine
 
 WORKDIR /backend
 

backend/Dockerfile.prod

@@ -1,4 +1,4 @@
-FROM node:20-alpine
+FROM node:22.23.4-alpine
 
 WORKDIR /backend
 

cms/Dockerfile.dev

@@ -1,4 +1,4 @@
-FROM node:20-alpine
+FROM node:22.23.4-alpine
 
 WORKDIR /cms
 

nginx/Dockerfile.prod

@@ -1,4 +1,4 @@
-FROM node:20-alpine AS cms-builder
+FROM node:22.23.4-alpine AS cms-builder
 
 WORKDIR /cms