OpenAPI generator ignores @discriminatorName and @caseName annotations for sealed traits

[wi101]

Describe the bug
When using zio-schema annotations (@discriminatorName, @caseName, @fieldName) on a sealed trait to define a discriminated union, the generated OpenAPI spec does not produce the expected oneOf with discriminator structure.

To Reproduce

import zio.http._
import zio.http.endpoint.Endpoint
import zio.http.endpoint.openapi.OpenAPIGen
import zio.schema.annotation.{caseName, discriminatorName, fieldName}
import zio.schema.{DeriveSchema, Schema}
import java.time.Instant

@discriminatorName("status")
sealed trait UserStatus

object UserStatus {
  @caseName("online")
  case class Online(d: Instant) extends UserStatus

  @caseName("offline")
  case class Offline(d: Instant) extends UserStatus

  @caseName("away")
  final case class Away(@fieldName("minutes") idleMinutes: Int) extends UserStatus

  implicit val schema: Schema[UserStatus] = DeriveSchema.gen[UserStatus]
}

case class User(name: String, status: UserStatus)
object User {
  implicit val schema: Schema[User] = DeriveSchema.gen[User]
}

// Endpoint using the types
val example = Endpoint(Method.POST / "example")
  .in[User]
  .out[UserStatus](Status.Ok)

// Generate OpenAPI
val openAPI = OpenAPIGen.fromEndpoints("Example API", "1.0.0", example)
println(openAPI.toJson)

api.yaml:

UserStatus:
  oneOf:
    - $ref: '#/components/schemas/Online'
    - $ref: '#/components/schemas/Offline'
    - $ref: '#/components/schemas/Away'
  discriminator:
    propertyName: status
    mapping:
      online: '#/components/schemas/Online'
      offline: '#/components/schemas/Offline'
      away: '#/components/schemas/Away'

    Offline:
      type: object
      properties:
        d:
          type: string
      required:
        - d
    Online:
      type: object
      properties:
        d:
          type: string
      required:
        - d
    Away:
      type: object
      properties:
        minutes:
          type: integer
          format: int32 
        

Note: But the referenced case schemas (Online, Offline, Away) are missing the discriminator property status:

Expected behaviour

Online:
  type: object
  properties:
    status:
      type: string
      enum: [online]
    d:
      type: string
  required:
    - status
    - d
...

Screenshots

Input (incorrect):

Output (correct):