Set EKS EOL to extended support end

[bakayolo]

Summary

• map EKS eol_date to endoflife.date extendedSupport so snapshots include the terminal extended-support end date
• keep eol as the EKS standard-support/deprecation boundary and preserve YELLOW extended-support classification/messages
• update EKS lifecycle tests and adapter docs to reflect current endoflife.date Amazon EKS semantics

Testing

• go test ./pkg/eol/endoflife ./pkg/config ./pkg/policy
• git diff --check
• Docker Compose detector-only EKS scan:
  • make compose-up EMITTER_PATH=/tmp/version-guard-emitter-not-present
  • POST /scan with {"resource_types":["eks"],"scan_id":"eks-eol-compose-test"}
  • verified snapshots/latest.json in MinIO had 156 EKS findings, missing_eol=0, status_counts={'GREEN': 42, 'YELLOW': 114}, and extended-support findings include non-null EOLDate (for example EKS 1.32: Status=YELLOW, EOLDate=2027-03-23T00:00:00Z, message Version 1.32 of eks is in extended support)