test(sql-orm-client): migration DDL + ORM include for implicit M:N

S4·M1 synthesises a model-less junction for an implicit many-to-many
(both navigable list ends bare, no junction model). This proves that
junction downstream: the migration system creates it, and the ORM
`include` walks it.

The `mn-psl-implicit` fixture authors `Post.tags Tag[]` / `Tag.posts
Post[]` with no junction model, emitted via the real pipeline for both
postgres and sqlite. The interpreter synthesises `_PostToTag` (composite
PK `(A, B)`, FK `A` → `posts.id`, FK `B` → `tags.id`) and lowers both
ends to `cardinality: 'N:M'` + `through` over it.

Migration DDL: the synthesised junction is a normal contract storage
table, so the migration planner creates it with no special-casing. A
migration test drives the real planner over each emitted contract against
an empty schema and asserts the `_PostToTag` `CREATE TABLE` (composite
primary key + the two foreign keys) is planned for postgres and sqlite.

Integration: an `include('tags')` test over the implicit M:N returns the
related rows (whole-row assertions, explicit + implicit select, PGlite),
walking the synthesised junction through a real emitted PSL contract with
no authored junction model.

Wires both emissions into the sql-orm-client emit script (so
`fixtures:check` regenerates them) and adds `@prisma-next/sqlite` to the
integration test package to emit the sqlite contract.

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 && 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 && 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",

pnpm-lock.yaml

@@ -44,6 +44,7 @@
     "@prisma-next/sql-relational-core": "workspace:0.14.0",
     "@prisma-next/sql-runtime": "workspace:0.14.0",
     "@prisma-next/sql-schema-ir": "workspace:0.14.0",
+    "@prisma-next/sqlite": "workspace:0.14.0",
     "@prisma-next/target-postgres": "workspace:0.14.0",
     "@prisma-next/adapter-mongo": "workspace:0.14.0",
     "@prisma-next/adapter-sqlite": "workspace:0.14.0",

test/integration/package.json

@@ -0,0 +1,35 @@
+// Real emitted fixture for the sql-orm-client implicit many-to-many parity
+// test — the `Post ↔ Tag` relation authored as two bare navigable list ends
+// with NO junction model.
+//
+// `Post.tags Tag[]` / `Tag.posts Post[]` are both bare (no `@relation(through:)`)
+// and no model links the pair, so the interpreter synthesises a model-less
+// junction table — Prisma's implicit many-to-many. The synthesised junction is
+// named `_PostToTag` (the two terminal model names ordered alphabetically) with
+// foreign-key columns `A` (→ `posts.id`) and `B` (→ `tags.id`) and a composite
+// `(A, B)` identity. Both list ends lower to a navigable `cardinality: 'N:M'`
+// relation with a populated `through` descriptor over `_PostToTag` — the same
+// runtime-consumable shape an authored junction emits — so the M:N ORM
+// `include` drives through a real emitted PSL contract with no authored
+// junction model.
+//
+// The synthesised junction is a physical table only (filtered out of `roots`),
+// so the migration system creates it like any contract storage table.
+
+model Post {
+  id    Int    @id
+  title String
+
+  tags Tag[]
+
+  @@map("posts")
+}
+
+model Tag {
+  id    String @id
+  label String @unique
+
+  posts Post[]
+
+  @@map("tags")
+}