fix: add Docker Compose V2 support for all management scripts

Add docker-compose-helper.sh to auto-detect and use:
- docker-compose (V1 - standalone)
- docker compose (V2 - plugin)

Update all 9 management scripts to use the helper:
- start.sh, stop.sh, restart.sh
- logs.sh, status.sh
- backup.sh, restore.sh, update.sh, cleanup.sh

This fixes "docker-compose: command not found" error on systems
with Docker Compose V2 installed.

Co-Authored-By: Claude Sonnet 4 <noreply@anthropic.com>

stop.sh

@@ -3,10 +3,14 @@
 
 set -e
 
+# 載入 docker compose 輔助函數
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/docker-compose-helper.sh"
+
 echo "🛑 停止 CodiMD 服務..."
 
 # 停止服務
-docker-compose down
+docker_compose down
 
 echo ""
 echo "✅ CodiMD 已停止"