Native skill downloader fails to handle in-repo symlinks (Error: Failed to download skill at path)

[peterfriese]

Describe the bug

When installing a skill that contains a symlink in its repository structure using Luca's native downloader, the installation fails with a Failed to download skill at path error.

This happens because the native downloader via the GitHub API doesn't appear to follow or resolve symlinks correctly, unlike the npx skills add bridge which handles them fine since it operates on a git clone.

To Reproduce

1. Attempt to install Paul Hudson's SwiftUI skill, which recently added a symlink pointing backwards to its references directory:
   luca install twostraws/SwiftUI-Agent-Skill
2. See error:
   Error: Failed to download skill at path 'swiftui-pro/references'.

Expected behavior

Luca should either natively resolve and copy the symlink target's contents, or properly recreate the symlink locally.

Workaround

Using the Vercel skills bridge bypasses the issue:
luca install twostraws/SwiftUI-Agent-Skill --use-npx

System Info

• Luca Version: 0.17.0
• OS: macOS