Add golden-range support for the TechVault environment pack

[Brad-Edwards]

Context

Issue #234 intentionally focuses on turning TechVault into a real, validated, self-contained scenario pack so APTL development can proceed. Golden-range behavior already exists in the sibling APTL repository on origin/dev, but porting or adapting it is not required to unblock that work.

Goal

Add the golden-range capability for TechVault after the validated scenario pack from #234 is available.

Reference

Use the sibling APTL repository and its origin/dev branch as the behavioral reference. Keep this repository subordinate to RAES core and within the environment-pack layout and tooling boundary.

Acceptance criteria

• Define the golden-range artifacts and workflow against the validated TechVault pack produced by Turn packs/techvault into a real, validated environment pack (assets + manifest + digests, no host paths, generated artifacts) #234.
• Preserve identity-and-digest-based artifact resolution with no host-path dependencies.
• Add automated validation and regression coverage for the golden-range behavior.
• Document the authoring and consumer contract needed by APTL.