redfish: MSI support, fix zero dates, BMC MAC, Assembly FRU, crawler cleanup

- Add MSI CG480-S5063 (H100 SXM5) support:
  - collectGPUsFromProcessors: find GPUs via Processors/ProcessorType=GPU,
    resolve serials from Chassis/<GpuId>
  - looksLikeGPU: skip Description="Display Device" PCIe sidecars
  - isVirtualStorageDrive: filter AMI virtual USB drives (0-byte)
  - enrichNICMACsFromNetworkDeviceFunctions: pull MACs for MSI NICs
  - parseCPUs: filter by ProcessorType, parse Socket, L1/L2/L3 from ProcessorMemory
  - parseMemory: Location.PartLocation.ServiceLabel slot fallback
  - shouldCrawlPath: block /SubProcessors subtrees
- Fix status_checked_at/status_changed_at serializing as 0001-01-01:
  change all StatusCheckedAt/StatusChangedAt fields to *time.Time
- Redfish crawler cleanup:
  - Block non-inventory branches: AccountService, CertificateService,
    EventService, Registries, SessionService, TaskService, manager config paths,
    OperatingConfigs, BootOptions, HostPostCode, Bios/Settings, OEM KVM paths
  - Add Assembly to critical endpoints (FRU data)
  - Remove BootOptions from priority seeds
- collectBMCMAC: read BMC MAC from Managers/*/EthernetInterfaces
- collectAssemblyFRU: extract FRU serial/part from Chassis/*/Assembly
- Firmware: remove NetworkProtocol noise, fix SecureBoot field,
  filter BMCImageN redundant backup slots

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

internal/parser/vendors/inspur/gpu_status.go

@@ -70,11 +70,13 @@ func applyGPUStatusFromEvents(hw *models.HardwareConfig, events []models.Event)
 					ChangedAt: e.Timestamp,
 					Details:   strings.TrimSpace(e.Description),
 				})
-				gpu.StatusChangedAt = e.Timestamp
+				ts := e.Timestamp
+				gpu.StatusChangedAt = &ts
 				currentStatus[idx] = newStatus
 			}
 
-			gpu.StatusCheckedAt = e.Timestamp
+			ts := e.Timestamp
+			gpu.StatusCheckedAt = &ts
 		}
 	}
 
@@ -85,7 +87,7 @@ func applyGPUStatusFromEvents(hw *models.HardwareConfig, events []models.Event)
 		} else {
 			gpu.ErrorDescription = ""
 		}
-		if gpu.StatusCheckedAt.IsZero() && strings.TrimSpace(gpu.Status) == "" {
+		if gpu.StatusCheckedAt == nil && strings.TrimSpace(gpu.Status) == "" {
 			gpu.Status = "OK"
 		}
 	}