Add MARK-based file organization guidance

Add SwiftUI view structure guidance

Add UserDefaults store guidance

Add reusable helper and extension guidance

Add guidance for small functions and unit tests

Add function formatting guidance to Swift style reference

Add debug output guidance to Swift style reference

Add SwiftUI ViewModel guidance to Swift skill

Add plugin packaging and OpenAI manifest for v1.0.1

Refine README installation links and remove unused asset

Merge remote initial commit

Initial release of Swift expert agent skill

Initial commit