Desktop Excel preview only shows the first worksheet and cannot switch sheets

What happened?

When opening an Excel .xlsx file with multiple worksheets in Codex Desktop preview, only the first worksheet is shown. I do not see a way to switch to the other worksheets, so the rest of the workbook is inaccessible from the preview.

Steps to reproduce

1. Open Codex Desktop.
2. Open a workspace containing an .xlsx file with two or more worksheets.
3. Open the .xlsx file in the built-in preview.
4. Try to view any worksheet other than the first one.

Expected behavior

The Excel preview should expose a way to switch worksheets, such as sheet tabs, a worksheet dropdown, or another navigation control. All worksheets in the workbook should be accessible from the preview.

Actual behavior

The preview only displays the first worksheet. Other worksheets are not visible and there is no obvious way to switch sheets.

Environment

• Codex Desktop: 26.623.81905 (build 4598)
• Platform: macOS 26.5.2 (build 25F84)
• Kernel/arch: Darwin 25.5.0 arm64 arm

Additional context

I searched existing issues for related terms such as xlsx preview sheet, spreadsheet preview sheet, only first sheet, worksheet tabs, sheet tab, multiple sheets, switch sheet, and worksheet preview. I found related Office/Excel preview issues, but not this specific multi-worksheet switching problem.

Related but different issues:

• #29966: Excel preview can show stale content after external edits.
• #29873: Office files behave differently depending on whether they are opened from output links or the workspace file picker.