implementation-kickoff

Explicitly invoke the skill after the implementation scope is agreed. It fetches origin/main, creates a detached worktree with git worktree add, keeps changes uncommitted, and finishes with one clean local commit on a suggested branch.

The skill refreshes the PR metadata and three-dot diff through read-only access, applies the complete task diff onto current origin/main, and records the original author as a verified Co-authored-by trailer. It never derives the branch from the contributor branch or preserves its commit topology.

No. The skill never pushes, opens a pull request, or mutates GitHub in any way. It ends with a local branch and one commit, and explicitly reports that nothing was pushed.

The skill stashes task changes, rebases the detached HEAD onto the new origin/main, reapplies the stash, and reruns formatting and focused checks. If conflicts are ambiguous, it preserves the stash and stops for user direction.

validate_handoff.py also detects hidden index states such as assume-unchanged flags, materialized skip-worktree paths, and dirty submodules that plain git status can miss. It also fails if committed paths do not exactly match the shipped-path manifest.