switch npm ci to npm install for Docker compat

admin/Dockerfile

@@ -1,7 +1,7 @@
 FROM node:22-alpine AS builder
 WORKDIR /app
 COPY package*.json ./
-RUN npm ci
+RUN npm install
 COPY . .
 RUN npm run build
 

backend/Dockerfile

@@ -1,7 +1,7 @@
 FROM node:22-alpine AS builder
 WORKDIR /app
 COPY package*.json ./
-RUN npm ci
+RUN npm install
 COPY . .
 RUN npx prisma generate && npm run build