Swift Concurrency Expert

**Judgement:** Strong, focused skill for addressing Swift Concurrency issues in Swift 6.2+ code, particularly around actor isolation, @MainActor usage, and Sendable correctness. Best suited for targeted concurrency remediation rather than broad architectural refactors. **Key strengths and risks:** - **Strengths:** Clear workflow (triage → smallest safe fix), emphasis on preserving behavior, and explicit guidance for UI-bound types, protocol conformances on actors, and global/static state. Good safety posture around Sendable and discouraging @unchecked Sendable without proof of thread safety. - **Risks/Limitations:** Text focuses on common patterns; it may not fully cover more advanced or niche concurrency features (e.g., complex task-group topologies, distributed actors, or deeply custom executors). Over-reliance on @MainActor or coarse actor isolation could introduce unnecessary serialization if not used judiciously. **Recommended scenarios:** - When Swift 6.2+ compiler diagnostics flag actor isolation, @MainActor, or Sendable issues and you need precise, minimally invasive fixes. - When migrating an existing UI or mixed codebase to modern Swift Concurrency and you want to enforce data-race safety without large-scale redesign. - When auditing concurrency around global/static state or cross-actor data sharing to reduce race conditions and make concurrency behavior explicit.