feat(skill-writer): skill-writer test recreates scope if already exists

[pixelastic]

Parent

#28

What to build

When skill-writer test is called with a scope that already exists, it must clean the existing scope before creating a new one.

This ensures each test call starts with a genuinely fresh subagent — no leftover worktree state, no old history.jsonl, no stale branch. The recreate must call the same logic as skill-writer clean to guarantee consistency.

Acceptance criteria

• skill-writer test --scope foo "..." called when ~/local/tmp/claude/skill-writer/foo/ already exists cleans the old scope first, then creates a new one
• The old history.jsonl is gone after recreate
• The old worktree and branch are removed before the new ones are created
• A fresh test on a new scope (no prior state) is unaffected

Blocked by

• feat(skill-writer): skill-writer test core #29
• feat(skill-writer): skill-writer clean subcommand #32