Correct Ana-side NAS identity: Debian 12, not TrueNAS

Network probes (no web admin, Debian SSH banner, only file-server ports
open) show 10.250.50.50 is vanilla Debian 12 with hand-configured NFS/SMB,
reprovisioned from the original TrueNAS SCALE install. Update stack
comments, README storage notes, Backrest description, proxmox-vms.md
entry for VM 100, and the restic configs intro to match.

Cross-site sync plan simplifies to plain rsync over SSH on both sides —
no appliance-specific tooling needed.

docs/pfi/proxmox-vms.md

@@ -16,13 +16,15 @@
 | **CPU** | 2 sockets × 2 cores = 4 vCPU (host passthrough) |
 | **Memory** | 8,196 MB |
 | **Disk** | `scsi0`: 80G on ospool |
-| **CDROM** | `ide2`: TrueNAS-SCALE-22.12.1.iso |
+| **CDROM** | `ide2`: TrueNAS-SCALE-22.12.1.iso _(original install media; current OS is Debian 12)_ |
 | **Network** | `net0`: virtio, MAC `9A:90:79:7A:86:87`, vmbr0, VLAN 50 |
 | **Boot** | scsi0 → ide2 → net0 |
 | **Startup** | Order 2, delay 120s |
 | **Onboot** | No |
 
-**Purpose**: TrueNAS SCALE storage appliance. Provides NAS/NFS/iSCSI to the colo environment.
+**Purpose**: NAS/NFS/SMB storage for the colo environment.
+
+**Current OS**: Debian 12 (bookworm), reprovisioned from the original TrueNAS SCALE install — SSH banner `OpenSSH_9.2p1 Debian-2+deb12u9`, no web UI on 80/443, no TrueNAS middleware. Shares are hand-managed via `/etc/exports` and `/etc/samba/smb.conf`. Mount paths kept the `/mnt/<pool>/…` shape of the original ZFS layout for host compatibility.
 
 ---
 
@@ -239,7 +241,7 @@ VMs without a startup order (103, 106, 107) will start based on their `onboot` s
 
 | VMID | Name | vCPU | RAM (MB) | Disk | OS |
 |---|---|---|---|---|---|
-| 100 | PFI-ANA-TRUENAS | 4 | 8,196 | 80G | TrueNAS SCALE |
+| 100 | PFI-ANA-TRUENAS | 4 | 8,196 | 80G | Debian 12 (reprovisioned from TrueNAS SCALE) |
 | 101 | PFI-ANA-DC | 12 | 24,576 | 240G | Windows 11 |
 | 102 | PFI-ANA-Docker | 8 | 16,384 | 250G | Linux |
 | 103 | PFI-SlaveBot | 8 | 8,192 | 256G | Windows 10 |