docs: [#428] close grafana checklist with follow-up #434

Author: josecelano

docs/issues/428-docker-vulnerability-analysis-apr8-2026.md

@@ -117,8 +117,8 @@ For each image, execute these steps in order:
 - [x] Image rebuilt and validated
 - [x] Trivy re-scan completed and compared
 - [x] Scan docs updated
-- [ ] Follow-up issue created (only if unresolved)
-- [ ] Image marked done
+- [x] Follow-up issue created (only if unresolved)
+- [x] Image marked done
 
 #### 8. MySQL (`mysql:8.4`)