[BUG][typescript-node] Default value missing when using allof

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When a property uses allof for common configuration (such as enum values) and a default, the default isn't set in the model.

What I get

'fruitType'?: FruitEnum;

Expected:

'fruitType'?: FruitEnum = FruitEnum.Apple;

openapi-generator version

6.6.0

OpenAPI declaration file content or url

openapi: "3.0.0"
info:
  version: "1.0.0"
  title: "Test default enum value"
paths:
  /eat:
    post:
      requestBody:
        content:
          application/json:
            schema:
              type: "object"
              properties:
                fruit_type:
                  allOf:
                  - $ref: '#/components/schemas/FruitEnum'
                  default: "apple"
      responses:
        200:
          description: "Yummy"

components:
  schemas:
    FruitEnum:
      type: "string"
      enum: [
          "melon",
          "apple"
        ]

This schema is based on schemas generated by drf-spectacular.

By the way, changing to the following does work:

fruit_type:
  allOf:
  - $ref: '#/components/schemas/FruitEnum'
  type: "string"
  default: "apple"

Generation Details

openapi-generator-cli generate -g typescript-node -i schema.yaml

Steps to reproduce

Generate the client code.

Related issues/PRs

#12634 is similar but not the same

Start by running the reported openapi-generator-cli command with the minimal schema and the typescript-node generator. Trace how the fruit_type allOf property is represented during generation, then verify that the generated TypeScript model includes the FruitEnum.Apple default while preserving the working non-allOf case.