- col_meta: add dim_group field to group related columns (dimension hierarchies, date-adjacent columns); is_key now enabled for date role to mark group parent
- sources.js: upsert includes dim_group
- Setup.jsx: group column in col_meta editor, key checkbox enabled for date role
- gen_dim_period.sql: create and populate pf.dim_period with calendar and fiscal period cuts (monthly grain, 2018-2035)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
