Groups allow multiple modules to be run sequentially in a defined order.
Adds full CRUD (repo, engine orchestrator, web routes, templates) for grp,
group_member, and group_run tables that were previously schema-only. Module
index now shows group membership badges per module. Wizard default dest name
now sanitizes source column names with spaces or special characters to valid
identifiers rather than failing at CREATE TABLE time.
Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>