Apply Creational Patterns for Complex Construction

Background: Native [platform] app, [Swift / Kotlin]. I have an object
that's painful to construct: [describe—many parameters, conditional
configuration, platform variants, or expensive setup]. Here's the
current code: [paste it].

Use case: Make construction clean and safe using the right creational
pattern.

Implementation details:
- Consider factory / factory method, builder, and (sparingly) singleton
- iOS: prefer Swift idioms—default arguments, static factory methods,
  result builders where they fit—before importing a heavy pattern
- Android/Kotlin: prefer named/default arguments, DSL builders, and
  companion-object factories
- Make illegal states unrepresentable where possible (types over runtime
  checks)

Deliverable: The refactored construction code using the recommended
pattern, an explanation of why it beats the alternatives here, and the
call sites updated to show how much simpler usage becomes.