fix: Dockerfile builder 단계에서 public 디렉토리 보장

- builder에서 mkdir -p로 public 디렉토리 생성 (앱에 없을 경우 대비)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -34,6 +34,9 @@ COPY . .
 RUN cd packages/database && npx prisma generate
 RUN pnpm turbo run build --filter=@relink/${APP_NAME}
 
+# Ensure public directories exist for COPY
+RUN mkdir -p /app/apps/${APP_NAME}/public
+
 # --- Stage 3: Runner ---
 FROM node:20-alpine AS runner
 ARG APP_NAME=web
@@ -44,9 +47,7 @@ RUN addgroup --system --gid 1001 nodejs
 RUN adduser --system --uid 1001 nextjs
 WORKDIR /app
 
-# Ensure public dir exists (some apps may not have one)
-RUN mkdir -p ./public
-COPY --from=builder /app/apps/${APP_NAME}/public/ ./public/
+COPY --from=builder /app/apps/${APP_NAME}/public ./public
 COPY --from=builder --chown=nextjs:nodejs /app/apps/${APP_NAME}/.next/standalone ./
 COPY --from=builder --chown=nextjs:nodejs /app/apps/${APP_NAME}/.next/static ./apps/${APP_NAME}/.next/static