Graphite

Drive the Graphite CLI (`gt`) for stacked pull-request workflows. Use when the user works with stacked PRs, mentions Graphite, gt, "the stack", or wants to create/submit/sync/restack/split/squash/fold branches. Triggers on `gt` commands, "stack of PRs", "stacked diffs", "trunk-based", `.graphite_repo_config`, branches prefixed by a Graphite user (e.g. `lms--`, `pp--`).

Configure a GitHub repository for Graphite — branch protection, merge queue, CI triggers, and stack-aware CI optimizations. Use when the user is onboarding a repo to Graphite, mentions Graphite branch protection / required checks / signed commits / merge queue, sees CI failing on `graphite-base/*` branches, asks about merge-queue choice (Graphite vs GitHub vs external), or wants to reduce CI cost for stacked PRs (CI Optimizations, stack-aware CI, `needs.optimize_ci.outputs.skip`). Triggers on `.github/workflows/*.yml` changes for repos using Graphite, the phrases "stack CI", "stacking and CI", "graphite-base", and any branch-protection or merge-queue discussion in a Graphite repo.

Operate the Graphite Merge Queue — enqueue PRs via label, dequeue, monitor queue status, and reason about stacked-PR queueing. Use when the user mentions Graphite merge queue, "merge when ready", queueing a PR, dequeueing, fast-track, the merge-queue label, "enqueue", "the queue", or when they ask to merge a PR/stack through Graphite (not directly). Triggers on phrases like "queue this PR", "add to merge queue", "enqueue stack", "remove from queue", "why didn't my PR merge", and on edits to `.please/config.yml` under `graphite.merge-queue`.