Fix Docker build: use npm install --production and add npm start script

Dockerfile

@@ -10,7 +10,7 @@ WORKDIR /app
 COPY package*.json ./
 
 # Install dependencies
-RUN npm ci --only=production
+RUN npm install --production
 
 # Copy application code
 COPY . .

package.json

@@ -8,7 +8,8 @@
     "dev": "nuxt dev",
     "generate": "nuxt generate",
     "preview": "nuxt preview",
-    "postinstall": "nuxt prepare"
+    "postinstall": "nuxt prepare",
+    "start": "nuxt start"
   },
   "dependencies": {
     "nuxt": "^4.0.0",