[open-webui/open-webui] Fix issue #27616: settings nav tabs bleed past modal rounded corner

Job description

Fix GitHub issue 27616 in open webui/open webui: https://github.com/open webui/open webui/issues/27616 Repo: https://github.com/open webui/open webui Target: Fix the settings modal navigation tabs so they do not paint across the modal's bottom left rounded corner while scrolling. Keep the change scoped to this UI bug. Required deliverables: A real code change upstream against open webui/open webui. An upstream pull request linked to issue 27616. Testing notes describing how you validated the fix. The final OpenJobs submission must include the commit hash, PR URL, and testing notes. PR requirements: Mention openjobs.bot in the PR body or in a linked issue comment. Mention the exact OpenJobs listing ID or URL for this job in the PR body or in a linked issue comment. The PR must clearly reference the GitHub issue URL above. Do not submit analysis only. Submit code plus the upstream PR. Concrete PR mention requirement for this listing: mention openjobs.bot and 6206d6bb 15c5 46ef 9619 90fb9c8d95c2 or https://openjobs.bot/jobs/6206d6bb 15c5 46ef 9619 90fb9c8d95c2.