Codify host validation profile for release installer runtime

[svelderrainruiz]

Summary

• add installer_contract.release_client.host_validation_profile to governance manifests
• make Install-WorkspaceInstallerFromRelease.ps1 validate and consume the host profile
• apply/restore deterministic env overrides (LVIE_INSTALLER_EXECUTION_PROFILE, LVIE_RUNNERCLI_EXECUTION_LABVIEW_YEAR, LVIE_GATE_SINGLE_PPL_BITNESS, LVIE_PARITY_WINDOWS_TAG) around installer execution
• extend release-client policy/runtime contract checks and tests to cover the new profile

Validation

• Invoke-Pester -Path ./tests/ReleaseClientPolicyContract.Tests.ps1,./tests/ReleaseClientRuntimeContract.Tests.ps1 -CI
• Invoke-Pester -Path ./tests -CI (241/241 passing)