gstack-merge gains confirm-enqueue: for a queue regime, confirm the PR was
actually picked up (Trunk Merge Queue (<base>) check appeared, or GitHub
auto-merge enabled) then RETURN, instead of blocking on the landing poll.
Writes a lightweight last-enqueue.json marker (no merge SHA). This is the
building block for /land's enqueue-and-return default; wait stays for --watch.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Pure regime logic in lib/merge.ts (detect/submit-plan/classify-land/handoff
schema+validation) behind a thin bin/gstack-merge CLI (detect/submit/wait/
write-state/read-state). Supports none, GitHub native merge queue, and the
trunk.io merge queue with a comment-first submit chain. 41 deterministic
tests (30 unit + 11 CLI).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Garry Tan