Override PayloadCMS Auto-Generated Fields While Preserving Default Options

[only-issues]

Hello PayloadCMS community and team, I'm not sure how to override automatically generated fields by Payload while still preserving the validation, hooks, and other default options except for the properties I want to override.

For example:

auth: {
  useAPIKey: true,
  loginWithUsername: {
    requireUsername: true,
    requireEmail: true,
    allowEmailLogin: true,
  },
  depth: 0,
  maxLoginAttempts: 5,
},

When I configure this in my Users collection, Payload automatically creates a username field, but I want to add some custom functionality to that field.

For example:

{
  label: 'My custom label',
  name: 'username',
  type: 'text',
  required: true,
  unique: true,
},

At this point, I'm unsure whether Payload still maintains the default TextField options for the username field or not.