[Bug]: Selected and hovered dropdown rows look identical when adjacent#19208

Before submitting

I searched existing issues and did not find a duplicate.
I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

Open a thread and open the diff panel.
In the scope dropdown, select "Latest turn".
Open the dropdown again and hover "Uncommitted", the row directly above.

Expected behavior

The selected row and the hovered row are distinguishable. The sidebar thread list stays readable in the same situation because it leaves a small gap between rows.

Actual behavior

The two rows get nearly identical backgrounds that touch with no gap, so they read as one tall highlight. The selected row has no other marker (such as a checkmark), so while hovering you can't tell which option is active.

The styling comes from the shared menu component (apps/web/src/components/ui/menu.tsx), so other dropdowns with a selected item likely behave the same way.

Possible fixes, for maintainers to choose: a gap between rows, a checkmark on the selected row, or a more distinct selected-row color.

Impact

Cosmetic issue

Version or commit

0.0.46-nightly.20261013.3066

Environment

macOS desktop app, Apple M5, dark theme