[Bash2.0] Opening the search overlay turns the right-side scrollbar gutter into a black bar

### Describe the issue

On kestra.io, opening the site Search overlay makes the vertical strip on the far right edge of the page turn into a solid black bar. With Search closed, the right edge shows the normal light scrollbar gutter. As soon as the Search overlay opens, that right-edge strip becomes black, sitting right next to the dimmed page behind the search dialog.

It looks like a scroll-lock issue: when the overlay opens and page scrolling is locked, the scrollbar gutter is left uncovered (or painted dark) so a black vertical bar appears against the rest of the dimmed page.

### Reproducibility

1. Open https://kestra.io (or any kestra.io page) on desktop with a visible scrollbar.
2. Note the far right edge (light scrollbar gutter).
3. Click the **Search** icon in the top nav to open the search overlay.
4. A solid black vertical bar appears on the far right edge, beside the search dialog, where the light gutter was.

See attached before/after screenshots.

Recording: https://jam.dev/c/1010eb80-fdaf-4230-857c-f626703023cf

### Environment

Site: https://kestra.io
Kestra Version context: 2.0.0-rc10 bug bash

Start by reproducing the issue on kestra.io using the Search icon and compare the page with the search overlay closed and open, including the right edge and scrollbar gutter. Trace the overlay's scroll-lock and dimmed-page behavior, then verify that opening Search no longer produces a black bar while the dialog and page remain usable.

Written by the indexing model from the issue text.