Column check introspection corrupts expressions with NOT VALID / NO INHERIT

[hsusul]

Bug

Column check is extracted by stripping a fixed prefix/suffix from pg_get_constraintdef(...), assuming the def is exactly CHECK (...).

When the constraint has a suffix (NOT VALID, NO INHERIT), the length heuristic returns a corrupted expression:

constraintdef	returned check
CHECK (id > 0) NOT VALID	id > 0) NOT VALI
CHECK (id > 0) NO INHERIT	id > 0) NO INHERI

Studio then shows / may round-trip an invalid check expression.

Repro

create table public.t (id int8);
alter table public.t add constraint t_id_check check (id > 0) not valid;

Then columns.retrieve / list — check is not id > 0.

Expected

check should be the expression only (id > 0), using pg_get_expr(conbin, conrelid) (with one outer paren pair stripped to preserve the existing API shape).