# Rule: git worktrees

This project teaches worktrees. It should use them properly.

## One task, one worktree, one agent

```bash
# from the main checkout
git worktree add ../af-task-07 -b refactor/task-07-route-cards
cd ../af-task-07
npm ci
```

Naming: directory `../af-task-NN`, branch `refactor/task-NN-<slug>`. Both
derived from the task file so the mapping is never ambiguous.

## Why isolation matters here

The migration runs many agents in parallel over the same small set of files
(`tokens.css`, `verify.mjs`, `astro.config.mjs` are contended). Worktrees give
each agent its own working directory over one object store — cheap, and no
agent can see another's half-finished state.

The failure mode without them: two agents both "fix" `verify.mjs`, and the
second overwrites the first's assertions.

## Contended files

These are touched by many tasks. Whoever owns them per the plan is the **only**
writer; everyone else opens an issue in their task report instead of editing:

| File | Owner |
| --- | --- |
| `src/styles/tokens.css` | `design-system-keeper` |
| `scripts/verify.mjs` | `verification-engineer` |
| `astro.config.mjs`, `package.json` | `astro-architect` |
| `src/content/config.ts` | `content-i18n-migrator` |

## Before you start

1. `git fetch origin && git rebase origin/main` — start from current `main`.
2. Read your task file end to end before writing anything.
3. Confirm your task's dependencies are merged. Task files list them.

## Before you finish

1. `npm run verify` green — without deleting assertions.
2. The relevant checklist in [`../checklists/`](../checklists/) complete.
3. `git rebase origin/main` again, resolve conflicts in your worktree.
4. Task report: what changed, what you verified, **what you did not do**.

## Cleanup

```bash
cd -                                    # back to the main checkout
git worktree remove ../af-task-07
git branch -d refactor/task-07-route-cards
```

Stale worktrees hold locks and confuse the next agent. `git worktree list`
should be short.

## Never

- Never work directly on `main`.
- Never force-push a shared branch. The `pages` branch is the sole exception,
  and only if CI owns it (see [`../context/publishing.md`](../context/publishing.md)).
- Never `git add -A` from the repository root. This repo has untracked local
  scratch (`.serena/`, `scripts/inspect.py`) that must not be swept into a commit.
