After making changes to the plugin source, reinstall to update the cached version:
# 1. Remove the installed cache
rm -rf ~/.claude/plugins/cache/*/workflow/
# 2. Reinstall from the local marketplace
claude plugin install workflowThe plugin cache lives at ~/.claude/plugins/cache/<marketplace>/workflow/<version>/. Skills, agents, and tools are copied there at install time, so any source changes require a reinstall.