feat(sql-orm-client): add User↔Tag M:N fixture via UserTag junction; re-emit contract

Adds a pure-junction UserTag model (userId/tagId, composite PK) and a
User.tags manyToMany relation to the sql-orm-client integration fixture.
Re-emits contract.json + contract.d.ts for both the integration test copy
and the package-local copy (with pgvector refs stripped).

The Tag model stays single-sided (no Tag.users reverse) to avoid a
MutationCreateInputWithRelations overload collision in the existing
collection-mutation-defaults tests.

Emitted via tsx script (c12 config loader unavailable in this sandbox);
verified additivity of the diff and round-trip via SqlContractSerializer.

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

Author: tensordreams

packages/3-extensions/sql-orm-client/test/fixtures/generated/contract.d.ts

@@ -64,6 +64,17 @@ const Tag = model('Tag', {
   },
 }).sql({ table: 'tags' });
 
+const UserTag = model('UserTag', {
+  fields: {
+    userId: field.column(int4Column).column('user_id'),
+    tagId: field.column(textColumn).column('tag_id'),
+  },
+})
+  .attributes(({ fields, constraints }) => ({
+    id: constraints.id([fields.userId, fields.tagId]),
+  }))
+  .sql({ table: 'user_tags' });
+
 const Post = PostBase.relations({
   comments: rel.hasMany(() => Comment, { by: 'postId' }),
   author: rel.belongsTo(UserBase, { from: 'userId', to: 'id' }).sql({ fk: {} }),
@@ -74,6 +85,11 @@ const User = UserBase.relations({
   invitedBy: rel.belongsTo(UserBase, { from: 'invitedById', to: 'id' }).sql({ fk: {} }),
   posts: rel.hasMany(() => Post, { by: 'userId' }),
   profile: rel.hasOne(() => Profile, { by: 'userId' }),
+  tags: rel.manyToMany(() => Tag, {
+    through: () => UserTag,
+    from: 'userId',
+    to: 'tagId',
+  }),
 }).sql({ table: 'users' });
 
 const baseContract = defineContract({
@@ -85,6 +101,7 @@ const baseContract = defineContract({
     Profile,
     Article,
     Tag,
+    UserTag,
   },
 });