fix wrapper script to use relative path on macos

[InfraWhisperer]

Summary

Fixes the macOS wrapper script to use relative paths instead of absolute paths, allowing the Sniffnet app to run from any location without requiring installation in the Applications folder.

Changes

1. Modified wrapper.sh to dynamically detect script directory using $(cd "$(dirname "$0")" && pwd)
2. Changed from hardcoded /*/Sniffnet.app/Contents/MacOS/sniffnet to relative path resolution
3. Used realpath to properly expand the path before passing to osascript to avoid variable expansion issues

Test plan

1. Verified path resolution works correctly from different directories
2. Confirmed osascript command formation is valid
3. Tested that the script no longer depends on specific installation location

Fixes: #898

[GyulyVGC]

Thanks for your attempt.
However, the realpath command seems to not be installed by default on all the macOS versions.
In fact I get this error: command not found: realpath.

[InfraWhisperer]

realpath

Sorry, my bad, I assumed realpath exists. I removed the usage of realpath and tested again. Please let me know if this works in your env too.

[GyulyVGC]

Nice, it now seems to work! Maybe it's worth it to use pwd -P to be sure that symbolic links are resolved.

[GyulyVGC]

It's also interesting to notice how your use of single & double quotes is finally expanding the variable, which is what I was failing to do.

I'm wondering whether we can be sure that the variable is expanded correctly in all the environments.

[GyulyVGC]

🚢

[GyulyVGC]

@all-contributors please add @InfraWhisperer for platform.

[allcontributors]

@GyulyVGC

I've put up a pull request to add @InfraWhisperer! 🎉