As a follow up to the possibility of sending the branch diff to an agent
review, this PR enables directly @-mentioning the content of your diff
with main to the agent. Here's a quick video of it:


https://github.com/user-attachments/assets/f27b7287-c9b9-4ccf-875e-4ac6ce4cd8ad

Release Notes:

- Agent: Enabled mentioning the branch diff with main.