Replaces CLI-based progress reporting (hai task update/log/create)
with custom tools registered on the worker's pi session. No PATH
dependency, no shell overhead, works in any worktree.
- task_update(step, status) — update step lifecycle
- task_log(message) — log actions and decisions
- task_create(description) — create tasks for out-of-scope work
- review_step unchanged (already a tool)
- System prompt and execution prompt updated to reference tools
b8d4853e85