The RBAC rework dropped the client_id read filter along with per-key client scope, so an all-clients key could no longer narrow to one client. apiClientScopeSql() now appends the filter after the scope fragment, so it can only narrow, never widen. Reads only - writes take client_id as their target client.
API keys now run as a user and inherit that user's module, operation, and client permissions. Drops per-key client scoping and removes existing keys (must be recreated). Adds an edit modal to change a key's user.
