[feat] Revive V1 commit history view in the Superset V2 interface #4935

Summary

Please bring back the V1-style commit history view in the Superset V2 interface, showing the workspace branch's commit history against the target/base branch as a first-class view.

Problem

In Superset V1, it was easy to inspect the current workspace branch's commits relative to the target branch. In the V2 interface, that capability appears to be hidden behind a dropdown instead of being directly visible.

This makes common review and workspace-management tasks harder:

• quickly understanding what changed in a workspace
• checking whether a branch is ahead/behind the target branch
• reviewing commit-by-commit progress before opening or updating a PR
• orienting in long-running agent-created workspaces

Requested behavior

Add a visible V2 commit history view that compares the current workspace branch against the target branch.

Ideally this should be available directly from the workspace/branch surface, not only tucked inside a dropdown.

Why this helps

• Restores an important V1 workflow in the V2 interface.
• Makes branch state easier to scan without leaving Superset.
• Helps users and agents verify work before PR creation or handoff.
• Reduces friction when managing many workspaces/tabs.

Acceptance criteria

• The Superset V2 interface exposes a first-class commit history view for the current workspace.
• The view is computed against the target/base branch, not just raw local commit history.
• Users can access it without discovering a hidden dropdown-only path.
• The view makes it clear which branch is being compared to which target branch.