Move-to-Worktree

Companion to /start-task for parallel Phase 4 lanes. /start-task leaves the primary checkout on the new feature branch; this skill moves that branch into its own worktree and puts the primary back on the default branch — one worktree + one branch + one agent session per in-flight issue.

Run (1 bash call)

bash {base_directory}/move-to-worktree.sh

No arguments — it operates on the branch currently checked out. The script:

1. Hard-stops unless run in the primary checkout, on a task branch ({type}/{issue#}/{slug}), with a clean tree and its upstream set to origin/<branch> literally (not a fork-style upstream remote) — i.e. exactly the state /start-task leaves behind. Also hard-stops unless .worktrees/ is gitignored: the worktree is nested inside the repo, so an unignored one gets staged by any git add -A as an embedded gitlink, committing this lane's HEAD onto another branch. Remedy is one line in .gitignore; the script never edits it for you.
2. Fetches origin/<branch> so the behind-check reflects reality, then pushes any local-only commits and checks out the default branch (this must happen before the worktree is created — git refuses to check out a branch in two places).
3. git worktree add .worktrees/<issue#> <branch> — nested inside the repo root, never a ../ sibling. The context file specs/context/<issue#>.md travels with the branch (it's committed). If this step fails, the script returns the primary checkout to the feature branch rather than stranding it on the default branch with no lane created.
4. Fast-forwards the default branch after the lane is parked. A failure here is reported as a warning, not an error — the move already succeeded.

Non-zero exit → hard-stop, print stderr verbatim.

Report

The script's summary block (worktree path, branch), plus: "Prepare the worktree as your project requires (install dependencies, configure ports, etc.), then open a new agent session there and continue the pipeline (/plan-architecture / /implement → /review → /commit → PR with Closes #N)."

When the PR has squash-merged, /finish-worktree <issue#> (run back in the primary) does the teardown.

You Must NOT

• Run the underlying git commands yourself — the script owns all mutation.
• Stash, discard, or commit anything to satisfy the clean-tree check — hard-stop instead.
• Edit .gitignore yourself to satisfy the gitignore check — report the remedy and stop.
• Move a branch whose upstream is ahead or does not match origin/<branch>.
• Create the worktree while the primary is still on the feature branch.
• Install dependencies, write port configuration, or otherwise touch the project's toolchain — that's the developer's job once the worktree exists.