# Task Plan — Issue #1: Create Extension File Structure

| Task | Description | TDD Status | Done |
|------|-------------|------------|------|
| 001.1 | Create extension file with correct imports and entry point | ✅ GREEN ✅ REFACTOR | ✅ |
| 001.2 | Register tool scaffolding (4 tools + command) with structured error returns | ✅ GREEN ✅ REFACTOR | ✅ |
| 001.3 | Implement `git_worktree_list` | ☐ RED ☐ GREEN ☐ REFACTOR | ☐ |

## Milestone Context (from implementation plan)

- **Milestone 1: Foundation** — Set up extension structure and register basic tools
- **Task 1.1**: Create Extension File — empty file with correct imports, loads without errors ✅
- **Task 1.2**: Register Tool Scaffolding — four tool registrations with placeholder execute functions (structured error returns) ✅
- **Task 1.3**: Implement `git_worktree_list` ☐

## Notes

- No traditional test framework — validation is: file exists at `.pi/extensions/pi-worktree.ts`, correct imports, pi loads without errors via `/reload` or restart.
- Single-file extension pattern: default export function receiving `ExtensionAPI`.
- Uses fj CLI for issue operations (auto-detected from git remote).