Fix Dockerfile on clean builds

Dockerfile

@@ -7,14 +7,11 @@ WORKDIR /app
 COPY backend/package*.json  ./backend/
 COPY frontend/package*.json ./frontend/
 
-# Install dependencies
-RUN cd backend  && npm ci
-RUN cd frontend && npm ci
-
 # Copy source files
 COPY . .
 
 # Build frontend and backend
+RUN npm install
 RUN npm run build --workspaces
 
 # Production stage