NetScore Netball Scoring

- Fixed crash reports — resolved two reported crash patterns: one that could occur when deleting match events, and another during automatic backup creation. These were caused by background data operations running on the wrong thread. (Thanks Mark H for the email that bought this to my attention) - Improved data safety — tightened Core Data concurrency across the app to prevent rare crashes during match scoring, settings changes, and backup/restore operations. - Updated for iOS 17.6 — raised the minimum iOS version from iOS 12 to 17.6 to align with Apple's current platform recommendations, security standards, and modern framework requirements. We know this affects users on older devices and we're sorry — we've held out as long as we could, but moving forward is necessary to keep the app secure and enable the features you've been asking for. - No changes to features or UI — everything works the same, just more reliably. Looking ahead — what's now possible with iOS 17: With this platform update we can finally replace ageing third-party dependencies with Apple's modern native frameworks: - Tips — migrating from the legacy EasyTipView library to Apple's built-in TipKit for richer, more reliable contextual guidance - Charts — moving from the external Charts library to Apple's native Swift Charts for smoother, more integrated statistics visualisations - Plus access to newer SwiftUI improvements and other iOS 17 framework enhancements that will make the app faster and more maintainable This will all help with the move and adoption of new iPhone devices and keep NetScore running well for many years to come. Thanks for using the app.