Improve PCIe inventory and hardware identity collection

audit/internal/collector/finalize_test.go

@@ -61,3 +61,20 @@ func TestFinalizeSnapshotPreservesDuplicateSerials(t *testing.T) {
 		t.Fatalf("duplicate serial should stay unchanged: %q", got)
 	}
 }
+
+func TestFilterPSUsKeepsSlotOnlyEntries(t *testing.T) {
+	slot := "0"
+	status := statusOK
+
+	got := filterPSUs([]schema.HardwarePowerSupply{
+		{Slot: &slot, HardwareComponentStatus: schema.HardwareComponentStatus{Status: &status}},
+		{HardwareComponentStatus: schema.HardwareComponentStatus{Status: &status}},
+	})
+
+	if len(got) != 1 {
+		t.Fatalf("len(got)=%d want 1", len(got))
+	}
+	if got[0].Slot == nil || *got[0].Slot != "0" {
+		t.Fatalf("unexpected kept PSU: %+v", got[0])
+	}
+}