Make system prompt be more explicit about root paths (#27383)

## Before

<img width="627" alt="Screenshot 2025-03-24 at 12 55 15 PM"
src="https://github.com/user-attachments/assets/349d7025-e65e-4107-86ae-45eb321003b3"
/>

## After

<img width="627" alt="Screenshot 2025-03-24 at 12 52 04 PM"
src="https://github.com/user-attachments/assets/0e8c061a-11c5-4d60-a694-55575b6c8f5e"
/>

Release Notes:

- N/A
4a5f89adedRichard Feldman committed on 3/24/2025, 6:00:16 PM· committed by GitHubparente661a0a
1 file changedLine totals unavailable