-- Venue modules: which optional modules the site admin has ACTIVATED (JSON array of
-- module ids, e.g. ["parking","validation"]). null = never set → everything the site is
-- entitled to (MODULES_ENTITLED env). Effective set = entitled ∩ activated, computed server-
-- side (apps/server/src/modules.ts); each change signs a config_change. Additive, nullable:
-- existing deployments see no behaviour change. See wiki/decisions/venue-modules.md.
ALTER TABLE `site_config` ADD `modules_json` text;