feat: replace Docker named volumes with local bind mounts and add backup script

- docker-compose.yml: sostituisce pgdata/uploads/caddy_data/caddy_config con bind mount su ./data/
- app/public/.gitkeep: crea cartella richiesta dal Dockerfile durante il build
- scripts/backup.sh: backup automatico di DB (pg_dump) e uploads con rotazione 30 giorni
- docs/BACKUP.md: guida completa backup, ripristino e setup cron
- .gitignore: aggiorna con data/ e backups/

scripts/backup.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
+BACKUP_DIR="${BACKUP_DIR:-$PROJECT_DIR/backups}"
+TIMESTAMP=$(date +%Y%m%d_%H%M%S)
+BACKUP_PATH="$BACKUP_DIR/$TIMESTAMP"
+
+mkdir -p "$BACKUP_PATH"
+
+echo "[1/2] Backup database..."
+docker compose -f "$PROJECT_DIR/docker-compose.yml" exec -T db \
+  pg_dump -U ecommerce ecommerce | gzip > "$BACKUP_PATH/db.sql.gz"
+echo "      → $BACKUP_PATH/db.sql.gz"
+
+echo "[2/2] Backup uploads..."
+if [ -d "$PROJECT_DIR/data/uploads" ] && [ "$(ls -A "$PROJECT_DIR/data/uploads")" ]; then
+  tar -czf "$BACKUP_PATH/uploads.tar.gz" -C "$PROJECT_DIR/data" uploads
+  echo "      → $BACKUP_PATH/uploads.tar.gz"
+else
+  echo "      (nessun file in data/uploads, saltato)"
+fi
+
+echo ""
+echo "Backup completato: $BACKUP_PATH"
+
+# Rimuovi backup più vecchi di 30 giorni
+find "$BACKUP_DIR" -maxdepth 1 -type d -mtime +30 -exec rm -rf {} + 2>/dev/null || true