chore: pin Node 24.15.0 in Docker and CI

.github/workflows/test.yml

@@ -12,7 +12,7 @@ jobs:
     
     strategy:
       matrix:
-        node-version: [24.x]
+        node-version: [24.15.0]
 
     steps:
       - name: Checkout code

backend/Dockerfile

@@ -1,7 +1,7 @@
 # Byggas från backend-mappen: docker build -t recipe-api:local .
 
 # Stage 1: Bygg applikationen
-FROM node:22-alpine AS builder
+FROM node:24.15.0-alpine AS builder
 WORKDIR /app
 
 # Kopiera backend-filer
@@ -19,7 +19,7 @@ RUN npm test
 RUN npm run build
 
 # Stage 2: Kör applikationen
-FROM node:22-alpine AS runner
+FROM node:24.15.0-alpine AS runner
 WORKDIR /app
 ENV NODE_ENV=production