feat: default todo message

[tlongwell-block]

Improve todo usage for autonomous work:

• Remove "2+ steps" threshold from todo instructions
• Show default reminder when todo is empty

Goose tends to forget requirements during longer autonomous tasks. This nudges it to write things down immediately rather than deciding whether a task is "complex enough" to warrant tracking.

[tlongwell-block]

/goose

[github-actions]

Summary: This PR improves todo usage for autonomous work by showing a default reminder message when the todo is empty and removing the "2+ steps" threshold from instructions. The changes are minimal, well-targeted, and align with the goal of nudging goose to document requirements immediately. The code is clean and follows existing patterns.

✅ Highlights

• Good use of existing infrastructure: The changes leverage the existing get_moim mechanism which is called by the extension manager to populate context. This is the right place to inject persistent reminders.

• Minimal, focused changes: Only two logical changes (remove threshold instruction + add default message), both directly addressing the stated problem.

• Clean refactoring: The get_moim refactoring from early-return style to a match expression improves readability by making the two cases (has content / no content) explicit and parallel.

• Appropriate default message: "Once given a task, immediately update your todo with all explicit and implicit requirements" is actionable and specific, which should be more effective than generic reminders.

---

Review generated by goose

[michaelneale]

is this missing some template wording @tlongwell-block ?

[tlongwell-block]

I think it's right in the diff. Just hard to grok in the unified view. I trimmed it down a lot because I think it was a bit repetitious