What kind of change does this PR introduce?

Bug fix.

What is the current behavior?

When a response decorator is configured with a built-in scalar (or array of scalar) type and an example payload, the example is silently dropped from the generated OpenAPI document.

@ApiOkResponse({ type: Number, example: 42 })
findAge() { ... }

The generated 200 response has no example:

{
  "description": "",
  "content": {
    "application/json": { "schema": { "type": "number" } }
  }
}

ResponseObjectFactory#create strips example and examples from the response via omit(response, exampleKeys) for the built-in-type branch, but it never re-attaches them to the generated media-type entry. The non-built-in (DTO) branch — handled by ResponseObjectMapper — already does the right thing via pick(response, exampleKeys) when it constructs the media type. The built-in-type branch is the outlier.

What is the new behavior?

example / examples are now forwarded to MimetypeContentWrapper.wrap for both the scalar and array-of-scalar built-in-type code paths, mirroring the DTO behaviour. The example ends up next to schema inside each content[<mimetype>] entry, as required by the OpenAPI spec, and is no longer left behind at the response top level.

{
  "description": "",
  "content": {
    "application/json": {
      "schema": { "type": "number" },
      "example": 42
    }
  }
}

Additional context (optional)

Added a focused unit test for ResponseObjectFactory covering scalar example, scalar examples, the isArray: true codepath, and a guard that example does not leak back to the top-level response object. The full swagger-explorer and response-object-mapper suites continue to pass (63 tests).