Choose the Right Pattern for a Problem

Background: Native [platform] app, [SwiftUI / Compose]. Here's a design
problem I'm facing: [describe the problem and what makes it awkward].

Current approach: [how it's done now, or "starting fresh"].
Pain points:
- [Issue 1]
- [Issue 2]

Use case: Tell me which design pattern(s) actually fit—or whether I
should use none and keep it simple.

Implementation details: Consider classic patterns (factory, builder,
strategy, adapter, decorator, observer, facade) and mobile-flavored ones
(repository, coordinator, use-case/interactor). For my top candidate,
show the Swift/Kotlin-idiomatic implementation—not a Java-style
translation.

Deliverable: For each viable pattern: how it maps to my problem, what the
idiomatic implementation looks like, the tradeoffs, and—importantly—when
it would be over-engineering. End with a clear recommendation.