model = "sonnet-4.6" is not a valid Claude CLI model identifier, causing all coder/qa/mergemaster agents to get 404 errors from the API and exit immediately with no work done. Change to "claude-sonnet-4-6". Also disable automatic worktree cleanup on archive so agent work can be inspected post-mortem. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>