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>

stacks/freedify/factory/main.tf

@@ -63,11 +63,11 @@ variable "ha_sofia_token" {
 }
 variable "nfs_music_server" {
   type    = string
-  default = "10.0.10.15"
+  default = "192.168.1.127"
 }
 variable "nfs_music_path" {
   type    = string
-  default = "/mnt/main/freedify-music"
+  default = "/srv/nfs/freedify-music"
 }