Markdown preview opened from Source Control lacks diff overview ruler

Does this issue occur when all extensions are disabled?: Yes/No

- VS Code Version: [enter version]
- OS Version: [enter OS and version]

Steps to Reproduce:

1. Configure `.md` files to open in Markdown Preview mode by default.
2. Make a change somewhere below the top of a Markdown file.
3. Open the Source Control view.
4. Click the changed Markdown file to inspect the change.
5. Observe the Markdown Preview scrollbar and the position of the changed content.

Expected behavior:

When a changed Markdown file is opened from Source Control in Markdown Preview mode, the preview should provide a clear way to locate the changes in the document.

The scrollbar area should show diff overview markers, similar to the overview ruler shown when viewing the file as source code. These markers make it possible to see where changes exist throughout the document and quickly navigate to them.

The preview should also reliably scroll so that the selected change is visible within the viewport.

Actual behavior:

Markdown Preview does not show any diff overview markers beside the scrollbar.

This means there is no visible indication of where changes are located within the document. Unlike the source-code diff view, the user cannot glance at the scrollbar or overview ruler to find the changed sections.

The automatic scrolling behavior is also inconsistent and makes the missing overview markers more problematic.

Sometimes the preview opens at the top of the file instead of at the change. Other times it scrolls near the changed section, but the actual changed content is positioned above the visible viewport. The result is that the user must manually scroll through the preview to locate the change.

The main issue is that Markdown Preview opened from Source Control is missing the diff overview/navigation markers available in the source-code view. The unreliable scrolling makes locating the selected change even more difficult.