parentId RESTRICT prevented Organization.deleteMany from clearing nested
folder trees during test resetDb, leaving half-wiped rows and breaking
subsequent upserts. Service still refuses non-empty folder deletes;
DB cascade only unblocks org teardown / full wipe.
Add a shared transparent OrganizationAgentConfigFolder tree for grouping
agent roles and skills in the admin UI without affecting identity, bindings,
run loading, or slash commands.