Pointsman 0.17.0

The GitHub connector can ask Copilot for a review (#220). Nothing changes until a deployment maps a decision action to the new action.

For deployments:

• Move ref in engine.json to the commit of v0.17.0. No migration, no new secrets, no new GitHub App permission or event.
• To use it: map a decision action to { "do": "copilot_review" } in GITHUB_CONNECTOR actions, only where your organization allows Copilot code review for every repository in repos. Limit how many commits get a review with skip_drafts and a rule on github_copilot (for example its reviews count), and keep a Copilot budget in the organization. Not yet tried with a GitHub App (only with github-actions[bot]): check the first request when you switch it on.

What changed:

• GitHub connector, copilot_review (#225): requests a review from Copilot with one fixed reviewer and no settings. At most one Copilot review per head commit, whoever asked (another profile or a person; Copilot known by its account id). Done only when GitHub's answer lists Copilot, otherwise shown on the check run as failed and not tried again for that commit. The pull request is read again right before, and nothing is asked if its head moved. Never for a fork's or a closed pull request. When the connector cannot tell whether Copilot was already asked, it asks nothing and looks again 10 minutes later.
• Not built from #220: CodeRabbit commands and paid reviews, because CodeRabbit ignores commands from a GitHub App. A person or an agent still posts them.
• Threat model: amended for copilot_review (Q44 to Q47); re-bound to this release in a separate pull request.