macOS: normalize working directory paths with FilePath

[bo2themax]

This fixes for Nushell when opening Ghostty via Finder service and Shortcuts, also makes path parsing more robust in AppleScript.

[jparise]

Do we also need the FilePath treatment in func application(_ sender: NSApplication, openFile filename: String), which also sets config.workingDirectory? That filename comes from app launch path.

[bo2themax]

Do we also need the FilePath treatment in func application(_ sender: NSApplication, openFile filename: String), which also sets config.workingDirectory? That filename comes from app launch path.

No, I checked that by dragging one on the dock icon, looks like AppKit already removed the trailing slashed.

But I'll double check for open command later.

[bo2themax]

Do we also need the FilePath treatment in func application(_ sender: NSApplication, openFile filename: String), which also sets config.workingDirectory? That filename comes from app launch path.

No, I checked that by dragging one on the dock icon, looks like AppKit already removed the trailing slashed.

But I'll double check for open command later.

Yes, the filename is already normalized, but I force pushed and moved the changes in set, so now it will normalized the new value regardlessly.