Add end-to-end integration test for @nonExposed decorator

[javiertoledo]

Summary

The @nonExposed decorator lacks an end-to-end integration test that verifies fields marked as non-exposed are actually excluded from the generated GraphQL schema.

Current State

• Unit tests verify that @nonExposed correctly registers field names in config.nonExposedGraphQLMetadataKey
• Tests cover @Entity, @ReadModel, @Command, and @Query class decorators
• However, the GraphQL generator tests stub out internals, so we don't have a test that:
  1. Defines a class with @nonExposed fields
  2. Generates the actual GraphQL schema
  3. Asserts the non-exposed fields are NOT present in the schema

Proposed Solution

Add an integration test that:

it('excludes @nonExposed fields from generated GraphQL schema', () => {
  @ReadModel({ authorize: 'all' })
  class TestReadModel {
    @field(type => UUID)
    public readonly id!: UUID

    @field()
    public readonly publicField!: string

    @nonExposed
    @field()
    public readonly secretField!: string
  }

  // Register the read model in config
  // Generate the GraphQL schema
  const schema = GraphQLGenerator.generateSchema(config)
  
  // Get the TestReadModel type from schema
  const testReadModelType = schema.getType('TestReadModel') as GraphQLObjectType
  const fields = testReadModelType.getFields()

  // Assert secretField is NOT in the schema
  expect(fields['publicField']).to.exist
  expect(fields['secretField']).to.be.undefined
})

Context

This was identified while fixing a timing bug in @nonExposed (commit ef27cb9). The fix is architecturally sound and follows the same pattern as @sequencedBy, but an integration test would provide additional confidence.

Files to Consider

• packages/core/test/services/graphql/graphql-generator.test.ts
• packages/core/test/services/graphql/graphql-query-generator.test.ts