Use a task-manager sub-agent to force one commit per task

A Claude Code user keeps tasks in a YAML todo file managed by a small Python script, and added a task-manager sub-agent with just two actions: fetch the next task and mark a task complete. Marking complete requires a commit ID, which pushes Claude Code into making one atomic commit per task. It gives tighter task-by-task control, though Claude Code still occasionally sidesteps the sub-agent and falls back to its built-in todo tool, so it needs watching.