Keep skipped ERT report check readable on development

[mickeynp]

Summary

• carry the static, human-readable gated ERT job name onto development
• prevent the unresolved matrix variable from appearing on skipped fork-PR report rows
• preserve versioned ERT reports and the no-checkout trust boundary

Validation

• actionlint 1.7.12
• git diff --check
• static assertions for the report display name, versioned reporter names, checks permission, and fork trust gate