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/parser/vendors/dell/parser.go

@@ -19,7 +19,7 @@ import (
 	"git.mchus.pro/mchus/logpile/internal/parser/vendors/pciids"
 )
 
-const parserVersion = "3.0"
+const parserVersion = "3.1"
 
 func init() {
 	parser.Register(&Parser{})
@@ -323,6 +323,7 @@ func parseCPUView(props map[string]string, result *models.AnalysisResult) {
 	if model == "" {
 		return
 	}
+	ppin := strings.TrimSpace(props["ppin"])
 	cpu := models.CPU{
 		Socket:       parseSocketFromFQDD(firstNonEmpty(props["fqdd"], props["instanceid"])),
 		Model:        model,
@@ -331,7 +332,8 @@ func parseCPUView(props map[string]string, result *models.AnalysisResult) {
 		Threads:      parseIntLoose(props["numberofenabledthreads"]),
 		FrequencyMHz: parseIntLoose(props["currentclockspeed"]),
 		MaxFreqMHz:   parseIntLoose(props["maxclockspeed"]),
-		PPIN:         strings.TrimSpace(props["ppin"]),
+		PPIN:         ppin,
+		SerialNumber: models.ResolveCPUSerialNumber(props["serialnumber"], ppin),
 		Status:       normalizeStatus(props["primarystatus"]),
 	}
 	result.Hardware.CPUs = append(result.Hardware.CPUs, cpu)