watchos-code-review

# watchOS Code Review ## Quick Reference | Issue Type | Reference | |------------|-----------| | App lifecycle, scenes, background modes, extended runtime | [references/lifecycle.md](references/lifecycle.md) | | ClockKit, WidgetKit, timeline providers, Smart Stack | [references/complications.md](references/complications.md) | | WCSession, message passing, file transfer, reachability | [references/connectivity.md](references/connectivity.md) | | Memory limits, background refresh, battery optimization | [references/performance.md](references/performance.md) | ## Review Checklist - [ ] SwiftUI App protocol used with `@WKApplicationDelegateAdaptor` for lifecycle events - [ ] `scenePhase` read from root view (not sheets/modals where it's always `.active`) - [ ] `WKExtendedRuntimeSession` started only while app is active (not from background) - [ ] Workout sessions recovered in `applicationDidFinishLaunching` (not just delegate) - [ ] Background tasks scheduled at least 5 minutes apart; next scheduled before completing current - [ ] `URLSessionDownloadTask` (not `DataTask`) used for background network requests - [ ] WidgetKit used instead of ClockKit for watchOS 9+ complications - [ ] Timeline includes future entries (not just current state); gaps avoided - [ ] `TimelineEntryRelevance` implemented for Smart Stack prioritization - [ ] WCSession delegate set before `activate()`; singleton pattern used - [ ] `isReachable` checked before `sendMessage`; `transferUserInfo` for critical data - [ ] Received files moved synchronously before delegate callback returns ## When to Load References - Reviewing app lifecycle, background modes, or extended sessions -> lifecycle.md - Reviewing complications, widgets, or timeline providers -> complications.md - Reviewing WCSession, iPhone-Watch communication -> connectivity.md - Reviewing memory, battery, or performance issues -> performance.md ## Review Questions 1. Is the app using modern SwiftUI lifecycle with delegate adaptor? 2. Are background tasks completing properly (calling `setTaskCompletedWithSnapshot`)? 3. Is UI update frequency reduced when `isLuminanceReduced` is true? 4. Are WatchConnectivity delegate callbacks dispatching to main thread? 5. Is `TabView` nested within another `TabView`? (Memory leak on watchOS)