feat: get_system_identity for matching a node to its BMC (0.2.0)

Mixes in napalm-device-types 4.9's SystemIdentityMixin over the exec
path, which runs as root: the node's SMBIOS system UUID, product serial
and board serial, vendor placeholders empty. pve-dual, a Supermicro
X10DRL-i, reports the product serial 0123456789; its board serial and
UUID are what tie it to its BMC.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "napalm-proxmox"
-version = "0.1.0"
+version = "0.2.0"
 description = "NAPALM driver for Proxmox VE (classic Linux networking, SDN, OVS)"
 readme = "README.md"
 license = { text = "Apache-2.0" }
@@ -25,7 +25,7 @@ classifiers = [
 requires-python = ">=3.9"
 dependencies = [
     "napalm>=5.0.0",
-    "napalm_device_types>=3.0.0",
+    "napalm_device_types>=4.9.0",
     "paramiko>=5.0.0",  # CVE-2026-44405; imported directly for SSH fallback (driver.py)
     "proxmoxer>=2.0.0",
     "netaddr>=0.9.0",