Review Branch: Code Review and Cleanup

Review every change the current branch introduces relative to main — committed AND uncommitted — for reuse, quality, and efficiency. Fix issues directly.

Phase 1: Identify Changes

1. Resolve the merge base against main:

   git merge-base main HEAD
   

2. If the current branch IS main (or no merge base differs from HEAD), tell the user there is nothing to review and stop.

3. Capture the cumulative diff (branch commits + working tree) into a temp file so the agents can read it without flooding your context:

   BASE=$(git merge-base main HEAD)
   git diff --no-color "$BASE" > /tmp/review_branch.diff