Function resolveYouTubeOptionalFieldValue

resolveYouTubeOptionalFieldValue(
    platformFields: YouTubeAccountDefaultsSeedTarget,
    field: "categoryId" | "defaultAudioLanguage",
    accountDefault: string,
): string
Resolves an optional YouTube string field for UI display. Account defaults apply only when the field is absent from stored platform JSON; an explicit null (user chose None) shows as unset without falling back.
Parameters
- platformFields: YouTubeAccountDefaultsSeedTarget
  Current platforms.youtube values.
- field: "categoryId" | "defaultAudioLanguage"
  Field key to resolve.
- accountDefault: string
  Fallback from YouTube account defaults.
Returns string
Trimmed string for the control, or undefined when unset/cleared.
- Defined in lib/platforms/youtube-account-defaults.ts:77