Apply critical security fixes and major improvements to all scripts

Security (CRITICAL):
- Add .env.example with strong password generation instructions
- Fix path traversal validation in restore.sh (now detects all .. patterns)
- Secure .env loading with set -a/set +a in all scripts
- Add logs/ to .gitignore to prevent credential leaks

Backup & Restore (IMPORTANT):
- Add file locking system to prevent concurrent backups
- Add disk space verification before backup operations
- Generate SHA256 checksums for all backups
- Verify checksums before restoration
- Create safety database backup before restore
- Implement comprehensive logging to ./logs/ directory
- Fix BACKUP_RETENTION_DAYS inconsistency
- Replace dangerous find -delete with safe iteration

Update & Recovery:
- Backup docker-compose.yml before updates with auto-rollback
- Add version display before/after updates
- Increase timeouts to 120s for slow containers
- Dynamic backup suggestion in recover.sh

Compatibility:
- Add Docker Compose v2 support with v1 fallback in all scripts
- Standardized log() function across all scripts

New Features:
- Add check-health.sh: comprehensive system health monitoring
- Add SECURITY.md: complete security documentation
- Update Makefile with check-health and recover commands
- Centralized logging with timestamps and levels

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

scripts/occ.sh

@@ -3,14 +3,20 @@
 
 set -euo pipefail
 
-# Vérifier que docker-compose est disponible
-if ! command -v docker-compose >/dev/null 2>&1; then
-  echo "❌ Erreur: docker-compose n'est pas installé"
+# Détecter docker-compose v1 ou docker compose v2
+DOCKER_COMPOSE=""
+if command -v docker >/dev/null 2>&1 && docker compose version >/dev/null 2>&1; then
+  DOCKER_COMPOSE="docker compose"
+elif command -v docker-compose >/dev/null 2>&1; then
+  DOCKER_COMPOSE="docker-compose"
+else
+  echo "❌ Erreur: Ni 'docker compose' (v2) ni 'docker-compose' (v1) n'est disponible"
+  echo "   Installez Docker Compose: https://docs.docker.com/compose/install/"
   exit 1
 fi
 
 # Vérifier que le container nextcloud est actif
-if ! docker-compose ps nextcloud | grep -q "Up"; then
+if ! $DOCKER_COMPOSE ps nextcloud 2>/dev/null | grep -q "Up"; then
   echo "❌ Erreur: Le container nextcloud n'est pas actif"
   echo "   Démarrez-le avec: make up"
   exit 1
@@ -18,4 +24,4 @@ fi
 
 # Exécuter la commande OCC
 # Le "$@" est sûr ici car il est passé directement à PHP OCC qui gère la validation
-docker-compose exec -u www-data nextcloud php occ "$@"
+$DOCKER_COMPOSE exec -u www-data nextcloud php occ "$@"