fix(parser): expose NVIDIA HGX tray/baseboard identity separately from vendor carrier FRU

Inspur/Kaytus onekeylog dumps only exposed the mechanical carrier FRU serial
(component/fru.txt Board Product) as board identity. That serial doesn't
change when the actual NVIDIA HGX baseboard (SXM+NVSwitch "delta board") is
swapped, causing false "board unchanged" conclusions. Parse the real HGX
tray/baseboard Model/PartNumber/SerialNumber triples from
HGX_HWInfo_FWVersion.log into a new HardwareConfig.HGX field, and normalize
Redfish's NA/N-A placeholders to empty across HGX identity parsing.

Closes #21

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/models/models.go

@@ -106,6 +106,26 @@ type HardwareConfig struct {
 	NetworkCards    []NIC            `json:"network_cards,omitempty"`
 	NetworkAdapters []NetworkAdapter `json:"network_adapters,omitempty"`
 	PowerSupply     []PSU            `json:"power_supplies,omitempty"`
+	HGX             *HGXIdentity     `json:"hgx,omitempty"`
+}
+
+// HGXAssemblyIdentity is the Model/PartNumber/SerialNumber triple for one
+// NVIDIA HGX Redfish assembly (tray or baseboard), read from HWInfo/FWVersion.
+type HGXAssemblyIdentity struct {
+	Model        string `json:"model,omitempty"`
+	PartNumber   string `json:"part_number,omitempty"`
+	SerialNumber string `json:"serial_number,omitempty"`
+}
+
+// HGXIdentity holds the NVIDIA HGX hardware identity as reported by the BMC's
+// HGX_HWInfo_FWVersion.log Redfish snapshot. This is distinct from BoardInfo:
+// BoardInfo/vendor FRU describe the mechanical carrier/tray shipped by the
+// server OEM (e.g. Inspur's YZCA-* part), which does not change when the
+// NVIDIA HGX baseboard ("delta board") itself is replaced. Tray/Baseboard
+// here are the actual NVIDIA-assigned identities that do change on a swap.
+type HGXIdentity struct {
+	Tray      HGXAssemblyIdentity `json:"tray,omitempty"`
+	Baseboard HGXAssemblyIdentity `json:"baseboard,omitempty"`
 }
 
 const (