post-merge-prune

name	post-merge-prune
description	Post-merge branch cleanup only. Use after a PR/MR is merged and the local feature branch is stale: prune remote refs and delete local branches already merged into the target branch.

Skill: post-merge-prune

[!IMPORTANT] LLM INSTRUCTION: This skill is a deliberate post-merge deletion tool. If the user invokes post-merge-prune, they want stale local branches removed after merge into the intended target branch. Do not offer a menu of options. Do not ask "Dry run or Execute?". Proceed directly.

Use this skill after a PR/MR has been merged into its intended branch, typically main, to remove stale remote-tracking refs and delete the matching local branches because the work is done.

Goal

• Switch to the intended target branch (main by default).
• Prune deleted remote branches.
• Delete local branches that are already merged into the target branch.
• Optionally remove matching workflow task folders.

Workflow

Step 1: Go to the target branch

• git checkout main (or the intended merge target)
• If the tree is dirty, stash first.

Step 2: Prune remote-tracking refs

• git remote update origin --prune
• This removes local refs for remote branches that were deleted after merge.

Step 3: Delete merged local branches

Iterate through local branches and delete the ones already merged into the target branch:

• Use git branch -d <branch> for normal merges.
• If -d refuses but git log main..[branch] is empty, the branch was squash-merged; use git branch -D <branch>.
• Never delete the active target branch.

Step 4: Optional workflow cleanup

If a deleted branch has a matching .workflow/tasks/* folder, remove it. If .workflow/active_task.json points to a deleted task, clear it.

Step 5: Verify

• git branch -a should no longer show deleted refs.
• git branch --merged main should only show branches you intend to keep.
• .workflow/tasks/ should not contain deleted tasks.

Guardrails

• RESOLUTION OVER REPORTING: If merge status is unclear, check git branch --merged main or git log main..branch and resolve it.
• NO DRY RUNS BY DEFAULT: Execute the cleanup unless the user explicitly asks for a preview.
• SMART DELETE: If a branch is squash-merged, delete it with git branch -D after confirming there are no unique commits left.
• ACTIVE BRANCH PROTECTION: Do not delete the current branch.
• UNMERGED WORK: If a branch has unique commits and no remote, ask once before force-deleting.

Output Contract

Return a concise report:

• Cleaned: deleted branches / task folders
• Kept: branches still in use
• Working Branch: the branch left checked out (should be main)