Adding a thread bubble is hidden when there is an existing comment on a line of code

Proposal

Make it clear on how to add a thread versus viewing existing open comments in diffs

1. Reposition the add thread button to the area between the line numbers and +/-
2. Update avatar to a button to show comments per line

Problem

Problem is that the button to add a thread is hidden when you go over a line with an existing comment.

@ms.mondrian duo reviewer comment is blocking the UI to start the thread on the same line CleanShot_2025-08-26_at_14.38.21

Designs

1. Mockups - Walkthrough to leave feedback
2. Figma
3. Explorations
4. Prototype

CleanShot_2025-10-01_at_00.44.37