The tool installer carries a second CI detector (internal/core/tools/install.go reads CI != "") beside the canonical one in internal/core/implement/load.go (ciRunner: GITHUB_ACTIONS=true, or CI other than empty, false or 0); the copy misses a runner that sets only GITHUB_ACTIONS, and two detectors drift. One primitive should serve both, with the installer keeping its stricter refusal of any non-empty CI.

The tool installer carries a second CI detector (internal/core/tools/install.go reads CI != "") beside the canonical one in internal/core/implement/load.go (ciRunner: GITHUB_ACTIONS=true, or CI other than empty, false or 0); the copy misses a runner that sets only GITHUB_ACTIONS, and two detectors drift. One primitive should serve both, with the installer keeping its stricter refusal of any non-empty CI.

Grounds

• pursued: one primitive answers is-this-CI for every verb that asks; a second detector reappearing, or an install proceeding with GITHUB_ACTIONS=true or any CI value set, would show it wrong