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>

restore.sh

@@ -3,6 +3,10 @@
 
 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"
+
 BACKUP_DIR="./backups"
 
 echo "🔄 CodiMD 還原腳本"
@@ -43,7 +47,7 @@ echo "🔄 開始還原..."
 
 # 1. 還原資料庫
 echo "📦 還原資料庫..."
-docker-compose exec -T database psql -U codimd codimd < "$BACKUP_DIR/$BACKUP_FILE"
+docker_compose exec -T database psql -U codimd codimd < "$BACKUP_DIR/$BACKUP_FILE"
 
 if [ $? -eq 0 ]; then
     echo "✅ 資料庫還原完成"