[tib8]

The "Wide details" layout first splits the screen to have maximize the width of the details area (the splits shown with red lines on the screenshot).
(some other PRs of mine are also visible on this screenshot)

The Vertical layout reserves sidebar width beside both the history tree and commit details. Add Wide Details under Advanced options > Layout so the sidebar and commit-search panel share the upper area with history, while commit details span the full repository content width below.

Keep Horizontal and Vertical available, persist the selected layout, and preserve sidebar resizing, search, details collapse, and page switching.

Validation:

• Based on the latest upstream develop (8f8aaea1), targeting develop as required by the contribution guidelines; contains one feature commit.
• Debug build: passed with 0 warnings and 0 errors, using a separate output directory.
• Layout regression checks: all 43 passed, including menu selection, panel bounds at two window widths, resizing, collapse, search, page switching, and preference persistence.
• dotnet format --verify-no-changes src/SourceGit.csproj --no-restore: passed.
• git diff --check upstream/develop...HEAD: passed.