Add method for using keys from github profile

[locus313]

No description provided.

[Copilot]

Pull Request Overview

This PR introduces a new ghuser method to fetch public SSH keys directly from a GitHub user’s profile, updates the configuration example, bumps the script version, and documents the change.

• Add ghuser fetch method in sync-ssh-keys.sh
• Update users.conf example to use ghuser
• Bump script version and expand README with new method

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
users.conf	Replaced admin entry with alice using ghuser
sync-ssh-keys.sh	Bumped version; renamed $URL to $TARGET; added ghuser branch with custom error handling
README.md	Documented the new ghuser method and updated usage

Comments suppressed due to low confidence (2)

sync-ssh-keys.sh:47

• [nitpick] The error message still refers to 'URL' even when the $TARGET may be a GitHub username. Consider changing the wording to 'target' or 'resource' to avoid confusion.

    log_message "Error: Unsupported method '$METHOD' encountered for URL '$TARGET'. Halting execution."

sync-ssh-keys.sh:38

• The new ghuser branch isn't covered by any tests. Adding unit or integration tests to simulate successful and failed key fetches for this method would help ensure future reliability.

  elif [[ "$METHOD" == "ghuser" ]]; then