bt6-merge-train

namespace	bt6-maintainer
name	bt6-merge-train
platforms	["all"]
description	Run an explicitly authorized, conservative BT6 merge train that processes validated pull requests one at a time and reconciles repository, CI, evidence, and issue state after each merge.
triggers	["bt6 merge train","merge validated BT6 pull requests","start a maintainer merge session","integrate ready research tool changes"]
requires	[{"current-queue-audit":"ready candidates with exact audited head SHAs"},{"explicit-merge-authorization":"operator authorizes repository, candidates, and mutation in the current context"},{"tracker-write-access":"configured canonical tracker actor may merge"}]
ensures	[{"dry-run-default":"no merge occurs unless explicitly authorized and dry-run is disabled"},{"one-at-a-time":"only one PR is merged before all relevant state is refreshed"},{"current-gates":"head, base, reviews, checks, risk-surface verification, and policy are rechecked immediately before merge"},{"reconciliation":"canonical branch, CI, linked issues, and queue state are checked after each merge"}]
commandHint	{"argumentHint":"<pr...> [--method squash|merge|rebase] [--dry-run] [--stop-on-conflict]","allowedTools":"Bash, Read","model":"sonnet","category":"release-management","modelRole":"reasoning","modelTier":"standard"}

BT6 Merge Train

Use only after bt6-queue-audit. Apply bt6-maintainer-guardrails.

Authorization preflight

Confirm the current operator explicitly authorized merging in the resolved repository. Record:

• canonical repository/tracker and expected actor;
• candidate PR numbers and audited head SHAs;
• base branch and permitted merge method;
• whether this is dry-run or live;
• current queue-audit reference and expiration conditions.

Approval to inspect, plan, review, fix, or prepare is not merge authorization.

Never merge

• requested-changes, draft, conflict/dirty, or ambiguous PR state;
• missing/failing required checks;
• head SHA different from the audited SHA;
• policy-disallowed merge method or unexpected base branch;
• unresolved security, privacy, citation, provenance, corpus, schema, data-loss, compatibility, or research-integrity finding;
• missing profile-required risk-surface verification;
• missing, stale, incomplete, or non-merge-ready external-provider assessment;
• a PR whose target repository/tracker/actor cannot be proven.

Candidate ordering

Respect dependencies and gate-critical fixes first. For otherwise independent work, prefer narrowly scoped docs/config, small verified defects, integrity and compatibility fixes, then larger features. Recompute ordering after each merge.

Per-PR procedure

1. Re-fetch PR metadata, exact head SHA, base, mergeability, reviews, required checks, linked issues, dependencies, and new human feedback.
2. Compare the head with the queue audit and PR-audit evidence.
3. Confirm hostile-input and all matched risk-surface checks are current.
4. Run any profile validation invalidated by base-branch movement.
5. For external-provider changes, confirm the provider assessment matches the exact head and its integration-complete and merge-ready verdicts are yes.
6. Verify the merge method is allowed and dry-run is false.
7. Merge exactly one PR through the canonical tracker.
8. Verify the resulting canonical-branch commit and post-merge CI.
9. Reconcile linked issues by observed state. Comment/close only when separately authorized; do not assume closing keywords worked.
10. Refresh base branch, open queue, reviews, checks, dependencies, and candidate ordering before considering another PR.

Stop conditions

Stop on any merge conflict, check failure, unexpected commit, issue mismatch, new feedback, stale audit, changed profile/policy, or ambiguous external state. Do not skip a failed candidate and continue unless the operator's authorization explicitly covers that behavior and remaining candidates are independent.