refactor(sql-orm-client): drop OrderByItem re-export, keep reverse() as the API

Re-exporting OrderByItem (and Direction) from the ORM client singled out
two AST types out of the whole alphabet that otherwise lives only in
@prisma-next/sql-relational-core/ast. .reverse() being an instance method
is enough: integrations call it on the item the orderBy selector already
returns, so no value-level import of OrderByItem is needed.

Move the public-shape type test to relational-core (OrderByItem.reverse()
returns OrderByItem; readable dir/expr) next to the runtime round-trip
test; drop the now-redundant sql-orm-client tests; reword the README
pagination note to use .reverse() inline.

TML-2596

Signed-off-by: Alexey Orlenko's AI Agent <robot@aqrln.net>

Author: tensordreams

…lient/test/order-by-item.types.test-d.ts …onal-core/test/ast/order.types.test-d.tspackages/3-extensions/sql-orm-client/test/order-by-item.types.test-d.ts renamed to packages/2-sql/4-lanes/relational-core/test/ast/order.types.test-d.ts packages/3-extensions/sql-orm-client/test/order-by-item.types.test-d.ts renamed to packages/2-sql/4-lanes/relational-core/test/ast/order.types.test-d.ts

@@ -1,6 +1,5 @@
-import type { AnyExpression } from '@prisma-next/sql-relational-core/ast';
 import { expectTypeOf, test } from 'vitest';
-import type { Direction, OrderByItem } from '../src/exports';
+import type { AnyExpression, Direction, OrderByItem } from '../../src/ast/types';
 
 test('OrderByItem.reverse() returns an OrderByItem', () => {
   expectTypeOf<OrderByItem['reverse']>().toEqualTypeOf<() => OrderByItem>();

packages/3-extensions/sql-orm-client/README.md

@@ -64,26 +64,25 @@ const posts = await db.Post
 `.orderBy(...)` accepts model-accessor callbacks that return `OrderByItem`s via the column's `.asc()` / `.desc()` helpers:
 
 ```ts
-const posts = await db.Post
+// Forward page (newest first).
+const firstPage = await db.Post
   .orderBy((post) => post.createdAt.desc())
   .take(10)
   .all();
 ```
 
-Integrations that own pagination — Relay-style backward cursor pagination, REST list endpoints — need to flip the user's sort order. `OrderByItem` (and its `Direction`) is re-exported from this package and exposes `.reverse()`, which returns a new frozen item with the direction flipped and the expression unchanged. Call it inside the `orderBy` selector to invert a user-supplied sort for a backward page:
+Integrations that own pagination — Relay-style backward cursor pagination, REST list endpoints — need to flip the user's sort order. Each `OrderByItem` exposes `.reverse()`, which returns a new frozen item with the direction flipped and the expression unchanged. Call it on the item the selector returns to build the backward page (then re-reverse the returned rows in application code):
 
 ```ts
-import type { ModelAccessor, OrderByItem } from '@prisma-next/sql-orm-client';
-
-type OrderSelector = (post: ModelAccessor<typeof contract, 'Post'>) => OrderByItem;
-
-const forward: OrderSelector = (post) => post.createdAt.desc();
-// Backward page: reverse the user's order, fetch, then re-reverse the rows in JS.
-const backward: OrderSelector = (post) => forward(post).reverse();
-
-const page = await db.Post.orderBy(backward).take(10).all();
+// Backward page: same sort, flipped.
+const lastPage = await db.Post
+  .orderBy((post) => post.createdAt.desc().reverse())
+  .take(10)
+  .all();
 ```
 
+An integration that wraps a user-supplied order selector flips it the same way — `(post) => userSelector(post).reverse()` — without having to inspect the opaque `OrderByItem`.
+
 ## Codec Roundtrip
 
 The runtime always awaits codec query-time methods, but rows yielded to user code carry **plain field values** — no `Promise`-typed fields ever reach `.first()` / `.all()` / streaming consumers, regardless of whether a column's codec is sync or async. This is true for both one-shot and streaming usage:

packages/3-extensions/sql-orm-client/src/exports/index.ts

@@ -1,5 +1,3 @@
-export type { Direction } from '@prisma-next/sql-relational-core/ast';
-export { OrderByItem } from '@prisma-next/sql-relational-core/ast';
 export { Collection } from '../collection';
 export { all, and, not, or } from '../filters';
 export { GroupedCollection } from '../grouped-collection';