claude@clouddev1
bbc2e34b33
Advanced-only `alter` entry word; ALTER TABLE <T> ADD COLUMN <col> <type> [constraints] | DROP COLUMN <col> | RENAME COLUMN <old> TO <new> -> SqlAlterTable, runtime-decomposed to the existing column executors (do_add_column / do_drop_column / do_rename_column) — one undo step each, no new worker layer. The COLUMN keyword is required (reserves bare RENAME TO for 4h, ADD CONSTRAINT for 4g). - ADD COLUMN takes NOT NULL / UNIQUE / DEFAULT / CHECK (no PK / inline REFERENCES). do_add_column extended to consume the SQL raw-text default_sql / check_sql (sql_expr is validate-only, the 4a.2 mechanism), reaching parity with CREATE TABLE's column constraints. - Drop/rename column refuse a column any CHECK references — table-level AND column-level (incl. a column's own self-check on rename) — the 4a.3 deferral, detected up-front by tokenizing the raw CHECK text (skipping string literals). In the shared executors, so it guards both the simple and SQL surfaces and fixes a latent rename-drift bug that desynced the stored CHECK text and broke rebuild. - SQL DROP COLUMN refuses an index-covered column (no --cascade SQL spelling — matches SQLite + the simple default). - The column executors and do_add_index gained an internal-__rdbms_* guard (refuse as "no such table"), closing a pre-existing exposure on both surfaces. (do_change_column_type / do_add_constraint / do_add_relationship are a tracked follow-up.) - `alter` is advanced-only; AlterTableAction::AddColumn is boxed (clippy::large_enum_variant). Docs: ADR-0035 status + §13 4e; ADR README; requirements.md Q1. Plan: docs/plans/20260525-adr-0035-sql-ddl-4e.md. Tests: 1854 passing / 0 failing / 0 skipped / 1 ignored; clippy clean.