refactor: properly gate platform specific code in AutoLaunchBuilder

[Legend-Master]

Referece: tauri-apps/plugins-workspace#1922 (comment)

[zzzgydi]

Thanks for the PR! The overall direction of gating platform-specific code behind cfg looks good, and moving os_info to a macOS-only dependency makes sense.

However, the branch currently fails to compile on macOS (CI didn't run on this PR, so it went unnoticed). The extracted free function app_name_path has two small issues:

1. The function body still references self.macos_launch_mode, but a free function has no self (E0424) — it should use the macos_launch_mode parameter instead;
2. At the call site in build(), self.macos_launch_mode is passed by value to a &MacOSLaunchMode parameter (E0308) — it needs to be &self.macos_launch_mode.

[Legend-Master]

Hey thanks for the quick response! I'm a bit used to fixing build on different platforms based on the CI since it's a bit easier than testing on multiple devices locally, please trigger the CI again, it should be fixed now.