Feature Request: Allow configuring base branch for 'Commit changes' diff view

Problem

The \"Commit changes\" diff view always compares against \main\, regardless of which branch you are currently on.

For users working on long-lived branches (e.g. \env/uat\), this is misleading — it shows a large diff of all changes since \main\ rather than actual uncommitted/unstaged changes.

Expected Behavior

Compare the diff against the current branch's remote tracking branch (e.g. \origin/env/uat\) instead of hardcoding \main\ as the base.

Alternatively, allow users to configure the base branch in Claude Code settings (e.g. \~/.claude/settings.json\).

Workaround

Use \git diff origin/<current-branch>\ in the terminal instead.

Environment

• Claude Code CLI
• Branch: \env/uat\