2e0969245c
- Add tkRestrict token to lexer - Parse ON DELETE CASCADE/SET NULL/RESTRICT and ON UPDATE CASCADE/SET NULL/RESTRICT in both table-level and column-level FK constraints - Add fkOnDelete/fkOnUpdate to ColumnDef and ForeignKeyDef - Fix table-level FK constraint application (third pass after columns are created) - Implement enforceFkOnDelete, enforceFkOnUpdate, enforceFkOnChildUpdate helpers - Wire FK enforcement into DELETE and UPDATE execution paths - Add 9 regression tests covering all FK actions