* ci: drop --delete-branch from reconcile auto-merge call
The reconcile job runs without a git checkout, so gh pr merge --delete-branch
fails with 'not a git repository' before enabling auto-merge. Auto-merge
itself needs no local git state; branch cleanup is already handled by the
PR-creating workflows.
* ci: checkout repo in bot auto-merge workflows
gh pr merge fails with 'not a git repository' when no checkout is present,
which prevented the reconcile job from enabling auto-merge. Restore the
checkout the previous approval workflow relied on.
* ci: auto-approve and auto-merge trusted bot pull requests
Replace the approve-only automatic-approval workflow with a combined
approve + enable-auto-merge workflow that also re-runs on every push,
plus a scheduled reconcile job that re-enables auto-merge for prepared
bot PRs if GitHub ever disables it. Bot PRs are gated to the known bot
actors, same-repo head, and base branch dev.
* ci: match bot authors by app slug in reconcile filter
gh pr list reports pull request authors of GitHub Apps as app/<slug>;
adjust the allowlist so the reconcile job actually matches bot PRs.
Thomas