deprecate TrueNAS: migrate Immich NFS to Proxmox, remove all 10.0.10.15 references [ci skip]

- Migrate Immich (8 NFS PVs, 1.1TB) from TrueNAS to Proxmox host NFS
- Update config.tfvars nfs_server to 192.168.1.127 (Proxmox)
- Update nfs-csi StorageClass share to /srv/nfs
- Update scripts (weekly-backup, cluster-healthcheck) to Proxmox IP
- Delete obsolete TrueNAS scripts (nfs_exports.sh, truenas-status.sh)
- Rewrite nfs-health.sh for Proxmox NFS monitoring
- Update Freedify nfs_music_server default to Proxmox
- Mark CloudSync monitor CronJob as deprecated
- Update Prometheus alert summaries
- Update all architecture docs, AGENTS.md, and reference docs
- Zero PVs remain on TrueNAS — VM ready for decommission

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/weekly-backup.sh

@@ -6,9 +6,9 @@ set -euo pipefail
 
 # --- Configuration ---
 BACKUP_ROOT="/mnt/backup"
-NFS_SERVER="10.0.10.15"
-NFS_BASE="/mnt/main"
-NFS_MOUNT="/mnt/nfs-truenas"
+NFS_SERVER="192.168.1.127"
+NFS_BASE="/srv/nfs"
+NFS_MOUNT="/mnt/nfs-proxmox"
 PVC_MOUNT="/tmp/pvc-mount"
 PUSHGATEWAY="${WEEKLY_BACKUP_PUSHGATEWAY:-http://10.0.20.100:30091}"
 PUSHGATEWAY_JOB="weekly-backup"