What problem does it solve? Pull request branch CI and merge-group CI test different things: the PR head in isolation versus a temporary merge of the PR head with the latest main. Integration tests that pass on the PR branch can fail in merge-group context, causing merge-queue kick-outs and wasted CI cycles. ## Core Features & Use Cases - Pre-queue merge simulation: Fetches latest main, merges the PR ref into a temporary detached worktree, and runs the full gate sequence (typecheck, lint, build, tests) against the merged result. - Automated command: The /swarm ci-simulate [<pr-ref>] command automates worktree creation, merge, gate execution, removal, and metadata pruning. - Manual fallback protocol: Step-by-step git worktree instructions for repos where the command is unavailable, including mandatory cleanup on every exit path. - Use Case: Before enqueueing a PR that touches shared integration test fixtures, run the simulation to catch test interactions exposed only by the merged result, fix failures on the PR branch, and re-simulate before queueing. ## Quick Start Ask the assistant to run the merge queue readiness simulation on the current pull request branch before adding it to the merge queue.
