Add: Nextcloud Backblaze B2 backup solution - automated daily backups

- Complete backup script for native Nextcloud (MySQL + files)
- Systemd service and timer for daily automated backups at 2 AM
- Backblaze B2 integration with secure credential storage
- Incremental backup support with 30-day retention
- zstd compression for 40-70% storage reduction
- Comprehensive documentation and deployment guides
- Successfully tested with first backup: 203MB DB + 1.3GB files
- Cost-optimized: ~/bin/bash.01-0.02/month for 1.5GB data

Deployment Details:
- Installed B2 CLI via pipx
- Created backup directories at /opt/nextcloud-backup/
- Configured systemd timer for daily execution at 2 AM
- First backup verified in B2 bucket: jg-nextcloud
- Automated scheduling enabled and tested

Documentation includes:
- Deployment report with complete setup details
- Quick start guide for future deployments
- Comprehensive technical reference
- Troubleshooting procedures
- File manifest and index

nextcloud-backup.env.configured

@@ -0,0 +1,70 @@
+# Nextcloud Backup Configuration (AUTO-GENERATED)
+# Created for VM103 (next) at 192.168.88.62
+
+# ============================================================================
+# NEXTCLOUD CONFIGURATION
+# ============================================================================
+
+# Path to docker-compose directory (or Nextcloud installation directory)
+# VM103 runs Nextcloud natively with Apache (not Docker)
+NEXTCLOUD_COMPOSE_DIR=/var/www/nextcloud
+
+# Full path to Nextcloud data directory
+# Local 2TB disk at /dev/sdb1, mounted as /mnt/nextcloud-data
+NEXTCLOUD_DATA_PATH=/mnt/nextcloud-data
+
+# Database configuration
+# MySQL on localhost, db 'nextcloud', user 'nextcloud'
+NEXTCLOUD_DB_NAME=nextcloud
+NEXTCLOUD_DB_USER=nextcloud
+NEXTCLOUD_DB_PASSWORD=Jogiocsi1211+
+NEXTCLOUD_CONTAINER=nextcloud
+
+# ============================================================================
+# BACKUP CONFIGURATION
+# ============================================================================
+
+# How many days to keep backups
+BACKUP_RETENTION_DAYS=30
+
+# Compression algorithm (zstd recommended)
+COMPRESSION=zstd
+
+# Directory to store local backup metadata and logs
+BACKUP_DIR=/opt/nextcloud-backup/.backups
+
+# Temporary directory for assembling backups
+TEMP_DIR=/tmp/nextcloud-backup
+
+# ============================================================================
+# BACKUP STRATEGY
+# ============================================================================
+
+# Backup type for scheduled backups (incremental or full)
+BACKUP_TYPE=incremental
+
+# Perform test/dry-run (no actual upload)
+DRY_RUN=false
+
+# ============================================================================
+# LOGGING & MONITORING
+# ============================================================================
+
+# Log level: DEBUG, INFO, WARN, ERROR
+LOG_LEVEL=INFO
+
+# Path to log files
+LOG_DIR=${BACKUP_DIR}/logs
+
+# Send alerts on failure (requires mail system configured)
+ALERT_EMAIL=jgitta@jgitta.com
+
+# ============================================================================
+# SCHEDULING (only used by systemd timer)
+# ============================================================================
+
+# Time for daily backup (24-hour format)
+BACKUP_TIME=02:00:00
+
+# Optional: Weekly full backup schedule
+FULL_BACKUP_DAY=Sunday