Fix backup script - resolve permission issues and restructure

Major fixes:
- Fix script structure: load .env before defining variables
- Remove duplicate color definitions (use common.sh)
- Fix permission issue: use sudo for du command on data/db dirs
- Add fallback to 2GB if disk space calculation fails
- Improve error messages and logging

The main issue was that data/ and db/ directories are owned by
different users (http, 999), causing du to fail even with stderr
redirection. Using sudo or || echo "0" fallback fixes this.

Tested: Backup now completes successfully with proper logging

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

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

scripts/backup.sh

@@ -1,46 +1,39 @@
 #!/bin/bash
-# ============================================
-# Script de sauvegarde Nextcloud
-# ============================================
-# Ce script crée une sauvegarde complète de:
-# - Données utilisateur
-# - Données utilisateur
+# scripts/backup.sh - Backup complet Nextcloud
 
 set -euo pipefail
 
-RED='\033[0;31m'
-GREEN='\033[0;32m'
-YELLOW='\033[1;33m'
-BLUE='\033[0;34m'
-NC='\033[0m' # No Color
-
-if [ -f .env ]; then
-  set -a
-  source .env
-  set +a
-else
-  echo -e "${RED}Erreur: Fichier .env non trouvé${NC}"
-  exit 1
-fi
-
-# Variables
-DATE=$(date +%Y%m%d_%H%M%S)
-MAINTENANCE_ENABLED=false
-
+# Variables globales
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
 cd "$PROJECT_ROOT"
 
+# Charger .env en premier
+if [ ! -f .env ]; then
+  echo "ERROR: Fichier .env introuvable"
+  exit 1
+fi
+
+set -a
+# shellcheck disable=SC1091
+source .env
+set +a
+
+# Configuration
+DATE=$(date +%Y%m%d_%H%M%S)
 LOCK_FILE="/tmp/nextcloud_backup.lock"
-
-LOG_DIR="${LOG_DESTINATION:-./logs}"
+LOG_DIR="./logs"
 LOG_FILE="$LOG_DIR/backup_$(date +%Y%m%d_%H%M%S).log"
-
 BACKUP_DIR="${BACKUP_DESTINATION:-./backups}"
 BACKUP_RETENTION_DAYS="${BACKUP_RETENTION_DAYS:-7}"
 BACKUP_NAME="nextcloud_backup_$DATE"
 BACKUP_PATH="$BACKUP_DIR/$BACKUP_NAME"
+MAINTENANCE_ENABLED=false
 
+mkdir -p "$LOG_DIR"
+
+# Charger les fonctions communes (log avec couleurs)
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/common.sh"
 
 if [ -z "${MYSQL_DATABASE:-}" ] || [ -z "${MYSQL_USER:-}" ] || [ -z "${MYSQL_PASSWORD:-}" ]; then
@@ -99,9 +92,11 @@ log "INFO" "Log file: $LOG_FILE"
 log "INFO" "Vérification de l'espace disque..."
 
 # Calculer l'espace requis (taille data + db avec 20% de marge)
-REQUIRED_SPACE=$(du -sb ./data ./db 2>/dev/null | awk '{sum+=$1} END {print int(sum*1.2)}')
+# Utiliser sudo pour accéder aux dossiers appartenant à d'autres utilisateurs
+REQUIRED_SPACE=$(sudo du -sb ./data ./db 2>/dev/null | awk '{sum+=$1} END {print int(sum*1.2)}' || echo "0")
 if [ -z "$REQUIRED_SPACE" ] || [ "$REQUIRED_SPACE" = "0" ]; then
-  REQUIRED_SPACE=1000000000  # 1GB par défaut si impossible de calculer
+  log "WARN" "Impossible de calculer l'espace requis (permissions?), estimation à 2GB"
+  REQUIRED_SPACE=2000000000  # 2GB par défaut si impossible de calculer
 fi
 
 # Obtenir l'espace disponible (enlever les espaces/newlines)