Root cause: addPeriodicTimeObserver's internal FigNotificationCenter weak
listener mechanism races with autorelease pool drain on main thread, causing
double-free of weak reference wrappers (KERN_INVALID_ADDRESS).
Changes:
- Replace addPeriodicTimeObserver with Timer.scheduledTimer (bypasses CoreMedia
weak listener infrastructure entirely)
- Remove ALL Task { @MainActor in } from observer callbacks — these created
unstructured tasks whose weak ref wrappers conflicted with CoreMedia internals
- Use DispatchQueue.main.async for KVO callbacks (may fire from non-main thread)
- Direct calls for queue: .main callbacks (NotificationCenter, end observer)
- Add isTearingDown flag to prevent callbacks firing during cleanup
- Fix cleanup() order: timer → KVO → notifications → replaceCurrentItem(nil)
- Fix FullscreenPlayerView: use addSublayer instead of replacing backing layer
- Add .onDisappear { bridge.cleanup() } to ensure cleanup before dealloc
- Remove Combine import (no longer needed)
- Remove Combine import and cancellables
- Use NSKeyValueObservation for timeControlStatus (controlled teardown)
- Invalidate itemStatusObserver before replacing playerItem
- Store endObserver token for proper removal
- Add cleanup() method called on view disappear
- Proper deinit with direct property cleanup (nonisolated-safe)
- UI defined in player.json (Bricks JSON schema)
- Custom widgets: VideoPlayer (AVPlayer layer), ProgressSlider (seek bar)
- PlayerBridge connects AVPlayer to BricksEngine event bus
- All interactions via binds/events (no imperative UI code)
- Depends on SwiftBricks SPM package
