[FEATURE]: Support table / column comments in schema & migrations (drizzle-kit)

### Feature hasn't been suggested before.

- [x] I have verified this feature I'm about to request hasn't been suggested before.

### Describe the enhancement you want to request

# Feature description

Currently, Drizzle ORM schema definitions do not provide a first-class way to define table comments and column comments that can be managed through drizzle-kit migrations.

In modern projects, database comments are no longer only for humans — they are increasingly important machine-readable context for AI-powered tooling.

I would like to request native support for defining and migrating comments directly in the schema layer.

# example API

```TypeScript
export const users = pgTable(
'users',
{
id: uuid('id').primaryKey().comment('Primary key'),
email: text('email').notNull().comment('User email address'),
createdAt: timestamp('created_at')
.notNull()
.defaultNow()
.comment('Account creation time'),
},
{
comment: 'Application users table',
}
);
```

# PostgreSQL example

```sql
COMMENT ON TABLE users IS 'Application users table';
COMMENT ON COLUMN users.email IS 'User email address';
```