Adds --serial flag and auto-detection (6+ agents) to run review agents
sequentially instead of in parallel, preventing context limit errors
with Opus 4.6.
Closes#166
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Create commands/ce/ directory with ce:plan, ce:work, ce:review,
ce:brainstorm, and ce:compound as the new primary commands.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>