feat(models): resolve CPU serial from source PPIN as common fallback

Centralize CPU identity in models.ResolveCPUSerialNumber: an explicit
source serial wins, otherwise a valid source PPIN is used, placeholders
rejected. Dell, H3C and Redfish apply it while parsing; canonical-device
and Reanimator conversion apply it again at the output boundary. No
identity is synthesized from socket/model/board serial.

See ADL-058.

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

internal/exporter/reanimator_converter.go

@@ -113,12 +113,13 @@ func buildDevicesFromLegacy(hw *models.HardwareConfig) []models.HardwareDevice {
 		details := mergeDetailMaps(nil, cpu.Details)
 		details = mergeDetailMaps(details, map[string]any{
 			"socket": cpu.Socket,
+			"ppin":   cpu.PPIN,
 		})
 		appendDevice(models.HardwareDevice{
 			Kind:             models.DeviceKindCPU,
 			Slot:             fmt.Sprintf("CPU%d", cpu.Socket),
 			Model:            cpu.Model,
-			SerialNumber:     cpu.SerialNumber,
+			SerialNumber:     models.ResolveCPUSerialNumber(cpu.SerialNumber, cpu.PPIN),
 			Cores:            cpu.Cores,
 			Threads:          cpu.Threads,
 			FrequencyMHz:     cpu.FrequencyMHz,
@@ -837,7 +838,10 @@ func convertCPUsFromDevices(devices []models.HardwareDevice, collectedAt, boardS
 			UncorrectableErrorCount: int64FromDetailMap(d.Details, "uncorrectable_error_count"),
 			LifeRemainingPct:        floatFromDetailMap(d.Details, "life_remaining_pct"),
 			LifeUsedPct:             floatFromDetailMap(d.Details, "life_used_pct"),
-			SerialNumber:            strings.TrimSpace(d.SerialNumber),
+			SerialNumber: models.ResolveCPUSerialNumber(
+				d.SerialNumber,
+				stringFromDetailMap(d.Details, "ppin"),
+			),
 			Firmware: firstNonEmptyString(
 				stringFromDetailMap(d.Details, "microcode"),
 				microcodeBySocket[socket],
@@ -1529,7 +1533,7 @@ func convertCPUs(cpus []models.CPU, collectedAt string) []ReanimatorCPU {
 			Threads:          cpu.Threads,
 			FrequencyMHz:     cpu.FrequencyMHz,
 			MaxFrequencyMHz:  cpu.MaxFreqMHz,
-			SerialNumber:     strings.TrimSpace(cpu.SerialNumber),
+			SerialNumber:     models.ResolveCPUSerialNumber(cpu.SerialNumber, cpu.PPIN),
 			Firmware:         "",
 			Manufacturer:     manufacturer,
 			Status:           cpuStatus,
@@ -2793,4 +2797,3 @@ func inferTargetHost(targetHost, filename string) string {
 
 	return ""
 }
-