A named NOT NULL column constraint refuses the whole table

On DoltgreSQL 1.3.1, a `CREATE TABLE` fails when a column's NOT NULL constraint has a name, as in
`id integer CONSTRAINT id_required NOT NULL`, and the table is not created:

```
ERROR: non-foreign key column constraint names are not yet supported
```

PostgreSQL 18.6 creates the table and keeps the constraint under that name.

## Reproduction

[`repro.sql`](https://github.com/Reliable-Collaboration/repro-doltgresql-bug-named-not-null/blob/main/repro.sql):

```sql
-- A NOT NULL column constraint with a name.
CREATE TABLE t (
id integer CONSTRAINT id_required NOT NULL,
v text
);

-- Was the table created?
SELECT table_name FROM information_schema.tables
WHERE table_name = 't';
```

## Expected behavior

The table is created, and the query finds it. This is what PostgreSQL 18.6 prints:

```
-- A NOT NULL column constraint with a name.
CREATE TABLE t (
id integer CONSTRAINT id_required NOT NULL,
v text
);
CREATE TABLE
-- Was the table created?
SELECT table_name FROM information_schema.tables
WHERE table_name = 't';
table_name
------------
t
(1 row)
```

## Actual behavior

The `CREATE TABLE` fails, and the query finds no table. This is what DoltgreSQL 1.3.1 prints:

```
-- A NOT NULL column constraint with a name.
CREATE TABLE t (
id integer CONSTRAINT id_required NOT NULL,
v text
);
psql:/tmp/repro.sql:5: ERROR: non-foreign key column constraint names are not yet supported
-- Was the table created?
SELECT table_name FROM information_schema.tables
WHERE table_name = 't';
table_name
------------
(0 rows)
```

## Run it

A runnable reproduction is at https://github.com/Reliable-Collaboration/repro-doltgresql-bug-named-not-null. Its script runs the test on PostgreSQL and DoltgreSQL in throwaway containers and prints the two outputs side by side:

```sh
git clone https://github.com/Reliable-Collaboration/repro-doltgresql-bug-named-not-null.git
cd repro-doltgresql-bug-named-not-null
./repro.sh
```

## Other observations

Each was run on DoltgreSQL 1.3.1 and on PostgreSQL 18.6, which accepted every statement below.

- The same error, and no table, for other names on a NOT NULL column constraint: the default name
(`id integer CONSTRAINT t_id_not_null NOT NULL` in table `t`), a quoted name
(`id integer CONSTRAINT "Id Required" NOT NULL`), a later column (`v text CONSTRAINT v_required NOT NULL`),
and a name after a default (`id integer DEFAULT 0 CONSTRAINT id_required NOT NULL`).
- `ALTER TABLE ... ADD COLUMN v text CONSTRAINT v_required NOT NULL` fails with the same error.
- Named `DEFAULT`, `UNIQUE`, `PRIMARY KEY` and `NULL` column constraints fail with the same error, for
example `id integer CONSTRAINT id_default DEFAULT 0`.
- Accepted: a named `CHECK` column constraint (`id integer CONSTRAINT id_positive CHECK (id > 0)`), a named
`REFERENCES` column constraint, a named generated column
(`g integer CONSTRAINT g_generated GENERATED ALWAYS AS (id + 1) STORED`), and named `CHECK`, `UNIQUE` and
`PRIMARY KEY` table constraints.
- Accepted without a name: `id integer NOT NULL`, and `ALTER TABLE ... ALTER COLUMN id SET NOT NULL`.
- The table-constraint forms of a named NOT NULL fail with a different error, `at or near "not": syntax error`:
`CONSTRAINT id_required NOT NULL id` inside `CREATE TABLE`, and
`ALTER TABLE ... ADD CONSTRAINT id_required NOT NULL id`.
- pg_dump 18.6 writes such a constraint the way this test does, `id integer CONSTRAINT id_required NOT NULL`,
also when it was created with a table-constraint form; with the default name, `t_id_not_null`, it writes
`id integer NOT NULL`.
- PostgreSQL 18.6 lists the constraint in `pg_constraint` as `id_required` with `contype` `n`; DoltgreSQL
1.3.1 lists no NOT NULL constraint there, not even for `id integer NOT NULL`.

## Possibly related

None found.

## Environment

- DoltgreSQL 1.3.1, the newest release when this was written: image `dolthub/doltgresql:1.3.1`, digest
`sha256:6c85cb1f35beabf47f094336a420255130b841b1645f36d79ef046276af36851`. Its bundled `psql` is 17.11.
- PostgreSQL 18.6: image `postgres:18.6-bookworm`, digest
`sha256:1c59e2c3c818eaa0f0628f695b36e7c9e362d6b219b36a54a32df645cbd7e1af`. Its `psql` is 18.6.
- Reproduced on 2026-09-11 (UTC) with Docker 29.7.2 on Linux x86_64 (Ubuntu 26.04.1 LTS under WSL 2).