[eagleoflqj]

Adds the initial Apple Silicon macOS client with a SwiftUI window, a link to the app recipe repository, and an error alert if the link cannot be opened.

Builds the app with CMake and Ninja using the Xcode SDK and Swift toolchain. Includes Release and Debug presets, bundle metadata, and development guidelines.

CI runs for pull requests, pushes to main, and manual dispatches. It uploads SimStore.app.tar.bz2 before running tests so failed tests still leave a downloadable build. Successful main runs create or update the latest tag and its release, titled Nightly build, with the current commit and archive.

Validation:

• Release build and window launch test passed on macOS 27.2.
• Bundle metadata test verifies that the Mach-O SDK version matches the selected SDK and that both Mach-O and Info.plist minimum OS versions match the deployment target.
• Deliberately mismatched SDK, Mach-O minimum OS, and Info.plist minimum OS values were rejected by the metadata test. macOS 14 runtime compatibility has not been tested.
• Archive extraction preserves the app executable. The release script's create and update paths passed local checks with a stub GitHub CLI.
• PR CI passed: the archive was uploaded before tests, both CTests passed, and publishing was skipped. Actual release publishing will run after merging to main.