Bringing a branch up to date

The coordinator names a commit hash. You merge that hash, and nothing else. Run each command as one plain call, never wrapped in Set-Location, Start-Process or cmd /c: the kit's tool (<kit>/tools/...) with -C <worktree> naming your worktree.

1. Commit work in progress by explicit path first (python <kit>/tools/commit.py -C <worktree> -m "<subject>" <path> ...): the tracked tree must be clean.
2. Untracked generated files the base now tracks make git refuse the merge: delete only those the repo profile's "Branches and worktrees" section names, nothing else.
3. Merge: python <kit>/tools/sync_base.py -C <worktree> <hash>. It fetches, refuses a hash not on the fetched remote main (do not substitute another: tell the coordinator), merges exactly that hash --no-ff, checks a clean merge for regrowth and adds the commit trailer.
4. Regrowth reported (a file the base shrank came back big, a stale branch reinstating deleted text): git checkout <hash> -- <path>, re-apply only your own change, commit it.
5. Conflicts (the merge is left in progress) in files you changed: resolve on your branch with your file-edit tool, one command per call, never a scratch script that rewrites a tracked file.
6. Conflicts in files you did not touch, or text you did not write: git merge --abort and tell the coordinator.
7. Docs and backlog-record conflicts: never keep both sides blindly; a union resurrects rows the base retired. Run git diff <hash> -- <file> and justify every printed line, deletions and additions; if you cannot, stop.
8. Finish a conflicted merge with python <kit>/tools/commit.py -C <worktree> -m "<subject>" <resolved path> ... (the repo's "commit".merge_fold lets the merge's own staged files through; the tool adds the trailer).
9. Re-gate the merged tree: python <kit>/tools/gate.py -C <worktree>; name the string that proves the merge is in the build.
10. Report the branch ready again, with the hash you merged and the gate's verdict line.

Never

• Rebase, merge local main or origin/... by name, force-push, reset or rewrite history. You do not push.
• git commit --no-edit (the safety check refuses it), or a commit identity the tool did not write.
• Resolve a conflict in someone else's change.

Details: <kit>/docs/sync-base.md; the repo profile, "Branches and worktrees".