docs(detector/vuls2): refresh enrichAdvisories/enrichCisco comments

Address Copilot review on PR #2581:
- enrichAdvisories doc comment now notes it enriches Cisco CveContent too, not
  just KEV.
- enrichCisco's "already present" note no longer cites the CPE detection path
  as the example (that path's sparse Cisco content is now deleted); make it
  generic (a higher-priority Cisco source on a prior call).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: shino

detector/vuls2/vendor.go

@@ -1177,7 +1177,8 @@ func enrichVulnerabilities(vi *models.VulnInfo, vulns []dbTypes.VulnerabilityDat
 	}
 }
 
-// enrichAdvisories enriches VulnInfo with advisory-based data (KEV).
+// enrichAdvisories enriches VulnInfo with advisory-based data: KEV, and the
+// Cisco CveContent (selected by source priority in the loop below).
 func enrichAdvisories(vi *models.VulnInfo, advisories []dbTypes.VulnerabilityDataAdvisory) {
 	for _, a := range advisories {
 		for sourceID, rootMap := range a.Contents {
@@ -1399,8 +1400,8 @@ func enrichNVD(vi *models.VulnInfo, rootMap map[dataTypes.RootID][]vulnerability
 // vulnerability stub, so this reads advisory roots. Cisco carries no CVSS — only
 // a vendor SIR, which the detection path surfaces as the DistroAdvisory severity
 // — so no CVSS is set here, matching go-cve-dictionary's ConvertCiscoToModel.
-// When a cisco CveContent is already present (e.g. from the CPE detection path)
-// it is left in place.
+// When a cisco CveContent is already present (e.g. populated by a
+// higher-priority Cisco source on a prior call) it is left in place.
 func enrichCisco(vi *models.VulnInfo, rootMap map[dataTypes.RootID][]advisoryTypes.Advisory) {
 	if _, ok := vi.CveContents[models.Cisco]; ok {
 		return