[bruno-archastro]

Summary

The installers currently bypass the CLI's placement question when run outside Git, without Node.js, or without a terminal: they pass --scope user automatically. That can install machine-wide hooks without a placement decision.

• Always ask interactive users whether hooks and skills should be global or repository-local.
• Require an explicit scope for unattended setup; --yes alone no longer chooses global scope.
• Explain missing Git/Node prerequisites for repository-local setup instead of falling back to global hooks.
• Preserve explicit scopes and CLI-only installation; update documentation and installer CI.

Verification

• 18 Unix installer PTY/process tests passed, including outside-repository, missing-Node, unattended/--yes, explicit-scope and interrupted-prompt cases.
• 5 cloud-installer contracts passed.
• Bash syntax, workflow YAML parsing and whitespace checks passed.
• Added PowerShell placement resolver contracts and Windows process coverage; local execution was unavailable, so Windows CI must verify them.

Compatibility and rollout

Unattended callers that install hooks must now pass --scope user or --scope repository (PowerShell: -Scope). --skip-setup/-SkipSetup remains available for CLI-only installation. The release smoke callers have a separate companion update and should be updated before this installer change is deployed. No rollout is claimed by this PR.

Agent session: 01a1a184-3305-73c2-acf4-7cdc75219e53