BUG: BUG: App crashes with EXC_BAD_ACCESS on macOS 26.0 beta during network download operations

[xijianchi]

Describe the bug
Sidekick application crashes with a segmentation fault (EXC_BAD_ACCESS) when performing network download operations. The crash occurs in the Swift runtime's memory management system during Key-Value Observation (KVO) notifications related to download progress tracking.

To Reproduce
Steps to reproduce the behavior:

1. Launch Sidekick app on macOS 26.0 beta
2. Initiate any network operation that involves file downloading with progress tracking
3. Wait for the download progress to update
4. App crashes with EXC_BAD_ACCESS exception at memory address 0x0000000000000428

Expected behavior
The app should handle network downloads and progress updates gracefully without crashing. Download progress should be displayed in the UI without memory access .

Desktop (please complete the following information):

• OS: macOS 26.0 (25A5349a) - Beta/Development version
• Hardware: Mac16,5 (M4 Max MacBook Pro, 128 GB RAM)
• Version: 1.0.0-rc.13 (build 33)

Smartphone (please complete the following information):
Not applicable - this is a macOS desktop application.

Additional context

• Crash occurs specifically in Thread 1 with swift_retain function failure
• Related to SwiftUI FoundationProgressView updates during network operations
• Call stack shows progression from NSURLSessionTask → NSProgress KVO → SwiftUI view updates → memory corruption
• May be related to concurrent access between network callbacks and UI thread
• The invalid memory address (0x428) suggests a null pointer dereference in Swift object retention
• This could be a compatibility issue with macOS 26.0 beta or a race condition in the app's memory management
• Full crash report available showing detailed call stack and memory state

[Tylast]

Still crashes on 26.0.1.