test(sql-orm-client): integration parity for arrow-path M:N include

Add a real emitted PSL fixture (mn-psl-arrow-path) authoring a Post <-> Tag
many-to-many over a relation-field-less PostTag junction via the quoted
arrow-path through: form, e.g.

  tags Tag[] @relation(through: "id -> PostTag.postId -> PostTag.tagId -> Tag.id")

with the mirror-imaged path on Tag.posts. The resolver builds the through
descriptor straight from the named columns and lowers both ends to
cardinality: 'N:M' + through over post_tags -- the same runtime-consumable
shape the authored-junction (mn-psl-through) and implicit (mn-psl-implicit)
forms emit.

Wire the fixture into the sql-orm-client emit chain so fixtures:check regen
covers it, and add a PGlite integration parity test that drives
db.orm.Post.include('tags') over the arrow-path M:N -- whole-row toEqual,
explicit .select() plus one implicit-selection readback -- proving the
column-based arrow-path contract drives the ORM include end-to-end.

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

Author: tensordreams

packages/3-extensions/sql-orm-client/package.json

@@ -7,7 +7,7 @@
   "description": "ORM client for Prisma Next — fluent, type-safe model collections",
   "scripts": {
     "build": "tsdown",
-    "emit": "cd ../../../test/integration && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/polymorphism/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/junction-namespaces/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/execution-defaulted-tags/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl-through/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/disambiguated-1n-inverse/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/self-ref-mn-through/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl-implicit/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl-implicit/prisma-next.config.sqlite.ts && cp test/sql-orm-client/fixtures/generated/contract.json test/sql-orm-client/fixtures/generated/contract.d.ts ../../packages/3-extensions/sql-orm-client/test/fixtures/generated/ && cp test/sql-orm-client/fixtures/junction-namespaces/generated/contract.json test/sql-orm-client/fixtures/junction-namespaces/generated/contract.d.ts ../../packages/3-extensions/sql-orm-client/test/fixtures/junction-namespaces/generated/ && cd ../../packages/3-extensions/sql-orm-client && node scripts/strip-pgvector-fixture.mjs test/fixtures/generated/contract.d.ts",
+    "emit": "cd ../../../test/integration && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/polymorphism/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/junction-namespaces/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/execution-defaulted-tags/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl-through/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/disambiguated-1n-inverse/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/self-ref-mn-through/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl-implicit/prisma-next.config.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl-implicit/prisma-next.config.sqlite.ts && node ../../packages/1-framework/3-tooling/cli/dist/cli.js contract emit --config test/sql-orm-client/fixtures/mn-psl-arrow-path/prisma-next.config.ts && cp test/sql-orm-client/fixtures/generated/contract.json test/sql-orm-client/fixtures/generated/contract.d.ts ../../packages/3-extensions/sql-orm-client/test/fixtures/generated/ && cp test/sql-orm-client/fixtures/junction-namespaces/generated/contract.json test/sql-orm-client/fixtures/junction-namespaces/generated/contract.d.ts ../../packages/3-extensions/sql-orm-client/test/fixtures/junction-namespaces/generated/ && cd ../../packages/3-extensions/sql-orm-client && node scripts/strip-pgvector-fixture.mjs test/fixtures/generated/contract.d.ts",
     "emit:check": "pnpm emit && git diff --exit-code test/fixtures/generated/ test/fixtures/junction-namespaces/generated/",
     "test": "vitest run",
     "test:coverage": "vitest run --coverage",

test/integration/test/sql-orm-client/fixtures/mn-psl-arrow-path/contract.prisma

@@ -0,0 +1,51 @@
+// Real emitted fixture for the sql-orm-client arrow-path many-to-many parity
+// test — the `Post ↔ Tag` relation authored over a relation-field-less
+// junction via the quoted arrow-path `through:` form.
+//
+// `PostTag` carries the scalar join columns `postId` / `tagId` plus a composite
+// `@@id`, but NO `post` / `tag` relation fields. The slice-2 relation-field
+// junction recognition can't fire (there are no relation fields to walk), so
+// the navigable M:N is declared on the terminal models with the quoted
+// arrow-path that names the join columns directly:
+//
+//   tags  Tag[]  @relation(through: "id -> PostTag.postId -> PostTag.tagId -> Tag.id")
+//   posts Post[] @relation(through: "id -> PostTag.tagId -> PostTag.postId -> Post.id")
+//
+// Path shape: `<localKey> -> <Junction.nearCol> -> <Junction.farCol> -> <targetKey>`.
+// Both ends carry their own mirror-imaged arrow-path (the junction has no
+// relation fields from which to infer an inverse). The resolver builds the
+// `through` descriptor straight from the named columns, lowering both ends to a
+// navigable `cardinality: 'N:M'` relation with a populated `through` descriptor
+// over `post_tags` — the same runtime-consumable shape an authored junction or
+// implicit M:N emits — so the M:N ORM `include` drives through a PSL contract
+// authored with the column-based arrow-path.
+//
+// `@@map` pins the storage tables (`posts` / `tags` / `post_tags`) and columns
+// (`post_id` / `tag_id`) so the integration schema setup and the emitted
+// `through` descriptor agree on names.
+
+model Post {
+  id    Int    @id
+  title String
+
+  tags Tag[] @relation(through: "id -> PostTag.postId -> PostTag.tagId -> Tag.id")
+
+  @@map("posts")
+}
+
+model Tag {
+  id    String @id
+  label String @unique
+
+  posts Post[] @relation(through: "id -> PostTag.tagId -> PostTag.postId -> Post.id")
+
+  @@map("tags")
+}
+
+model PostTag {
+  postId Int    @map("post_id")
+  tagId  String @map("tag_id")
+
+  @@id([postId, tagId])
+  @@map("post_tags")
+}