[FEATURE] Desktop: expand a commit in the diff view's Commits list to show full message body, author, and date

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

In the Claude Code desktop app's diff view, the Commits list shows only the subject line of each commit. There is no way to see the full commit message body in the UI.

Claude often writes multi-paragraph commit messages, and the body is where the reasoning lives. To review what it wrote, I have to leave the app and open the commit on GitHub. That interrupts the review flow, and it only works once the commit has been pushed.

Proposed Solution

Let me expand a commit in the Commits panel to reveal the full commit message body, the author, and the commit date. Any of these interactions would work:

• Click the commit row to expand it in place.
• Hover to show the details.
• Right-click the commit and choose "View full commit message", which expands it.

The collapsed state stays as it is today (subject line only), so the list remains compact.

Nice to have, as a follow-up: from the expanded view, let me suggest changes to the commit message (for example, edit the text and send it to Claude to amend or reword the commit), so I can fix a message without leaving the review flow.

Alternative Solutions

Today I open the commit on GitHub to read the full message. It works, but it takes me out of the app, and the commit has to be pushed first.

Priority

Medium - Would be very helpful

Feature Category

Other

Use Case Example

1. Claude makes several commits during a session.
2. I open the diff view and scan the Commits list.
3. A subject line looks interesting, and I want to check the reasoning in the body.
4. Today I have to go to GitHub to read it. With this feature, I'd expand the commit in place. If the message needs rewording, I'd suggest the change right there.

Additional Context

Applies to the desktop app (Code tab). Similar to the expandable commit rows in GitHub's PR commit list and in most Git GUIs.