fix(docker): use npm ci inside image instead of copying host node_modules

Dockerfile

@@ -17,9 +17,9 @@ COPY .next/standalone/ ./
 COPY .next/static ./.next/static
 COPY public ./public
 
-# Copy all production node_modules from build context
-# (pre-installed via npm ci --omit=dev before docker build)
-COPY node_modules ./node_modules
+# Install production dependencies inside Docker
+COPY package*.json ./
+RUN npm ci --omit=dev && npm cache clean --force
 COPY prisma ./prisma
 
 # Fix Turbopack's hashed Prisma client path (if .next inside standalone)