fix: get_facts() reads physical hardware info from DMI sysfs via SSH

vendor, model and serial_number now come from /sys/class/dmi/id/
(sys_vendor, product_name, product_serial) via SSH, reflecting the
actual physical server rather than the Proxmox software layer.

Falls back to "Proxmox Server Solutions GmbH" / status.model if SSH
or DMI files are unavailable (e.g. bare-metal without SSH creds).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

napalm_proxmox/driver.py

@@ -332,14 +332,18 @@ class ProxmoxDriver(
     # ------------------------------------------------------------------ #
 
     def get_facts(self) -> _JsonDict:
-        """Return basic facts about the Proxmox node."""
+        """Return basic facts about the Proxmox node.
+
+        Hardware vendor, model and serial are read from the Linux DMI sysfs
+        entries (``/sys/class/dmi/id/``) via SSH so they reflect the physical
+        machine, not the Proxmox software layer.
+        """
         status = self._get_node_status()
         version = self._get_version_info()
         network = self._get_node_network()
         dns = self._get_node_dns()
 
         uptime = float(status.get("uptime", 0))
-        model = status.get("model", "")
         dns_search = dns.get("search", "")
         hostname = self._node_name
         fqdn = f"{self._node_name}.{dns_search}" if dns_search else self.hostname
@@ -352,14 +356,34 @@ class ProxmoxDriver(
         release = version.get("release", "")
         os_version = f"Proxmox VE {pve_version}" if pve_version else f"Proxmox VE {release}"
 
+        # Physical hardware info from Linux DMI sysfs
+        vendor = ""
+        model = ""
+        serial = ""
+        try:
+            dmi_cmd = (
+                "printf '%s\\t%s\\t%s' "
+                "\"$(cat /sys/class/dmi/id/sys_vendor 2>/dev/null)\" "
+                "\"$(cat /sys/class/dmi/id/product_name 2>/dev/null)\" "
+                "\"$(cat /sys/class/dmi/id/product_serial 2>/dev/null)\""
+            )
+            raw = self._exec_ssh_command(dmi_cmd).strip()
+            parts = raw.split("\t")
+            if len(parts) >= 3:
+                vendor = parts[0].strip()
+                model = parts[1].strip()
+                serial = parts[2].strip()
+        except Exception as exc:
+            logger.debug("Failed to read DMI info via SSH: %s", exc)
+
         return {
             "uptime": uptime,
-            "vendor": "Proxmox Server Solutions GmbH",
+            "vendor": vendor or "Proxmox Server Solutions GmbH",
-            "model": model or "Proxmox VE Node",
+            "model": model or status.get("model") or "Proxmox VE Node",
             "hostname": self._node_name,
             "fqdn": fqdn or self.hostname,
             "os_version": os_version,
-            "serial_number": "",
+            "serial_number": serial,
             "interface_list": iface_list,
         }