Use npm install instead of npm ci (no lockfile)

Dockerfile

@@ -2,7 +2,7 @@
 FROM node:22-alpine AS frontend-build
 WORKDIR /app/frontend
 COPY frontend/package.json frontend/package-lock.json* ./
-RUN npm ci
+RUN npm install
 COPY frontend/ ./
 RUN npm run build
 # Output: /app/static/