Agent Skills: dependency-injection

Expert DI decisions for iOS/tvOS: when DI containers add value vs overkill, choosing between injection patterns, protocol design for testability, and SwiftUI-specific injection strategies. Use when designing service layers, setting up testing infrastructure, or deciding how to wire dependencies. Trigger keywords: dependency injection, DI, constructor injection, protocol, mock, testability, container, factory, @EnvironmentObject, service locator