fix(ui): prevent middle-click scroll when closing tabs

[HRronaldo]

Summary

Fixes #15077

Problem

Middle-clicking a tab while the tab bar is scrollable doesn't close it.

Solution

Added an onMouseDown handler that calls preventDefault() for middle-click (button === 1), preventing the default scroll behavior before onAuxClick fires.

Changes

• packages/ui/src/components/tabs.tsx: Added onMouseDown handler to prevent scroll on middle-click

Testing

1. Open enough files to make the tab bar scrollable
2. Middle-click a tab to close it
3. Tab should close successfully without triggering scroll

Verification

• Code follows project style guide
• No new lint errors

[github-actions]

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[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Potential Duplicate Found:

• PR fix(app): middle-click tab close in scrollable tab bar #15081: "fix(app): middle-click tab close in scrollable tab bar"
  • URL: fix(app): middle-click tab close in scrollable tab bar #15081

Why it's related: Both PRs address the exact same issue - preventing middle-click scroll behavior when closing tabs in a scrollable tab bar. PR #15081 appears to be an earlier or parallel attempt to fix issue #15077, covering the same root cause (middle-click triggering scroll before onAuxClick fires).