ADR-0028 complete (per handoff-21); ADR-0029 (column
constraints) written, accepted, and implemented through
commit 4 of 6 — NOT NULL / UNIQUE / DEFAULT / CHECK at
`create table` and `add column`. Commits 5 (`add constraint`
/ `drop constraint` + the §5 dry-run) and 6 (friendly errors
+ typing-surface matrix) are planned in full in §4.
claude@clouddev1