Add desktop-notify skill (macOS/Linux)

[graysurf]

Summary

This PR adds a new experimental skill: desktop-notify, which lets Codex (or any agent workflow) send a short desktop notification on macOS and Linux. I use this when Codex runs long tasks so I can see completion status immediately.

External dependencies / Install hints

This skill relies on OS-specific notification utilities:

• macOS: brew install terminal-notifier
• Linux (Debian/Ubuntu): sudo apt-get install libnotify-bin
• Linux (Fedora): sudo dnf install libnotify

If the backend is missing, the scripts default to a silent no-op.

What’s included

• scripts/desktop-notify.sh
  • Sends a notification with an explicit --title, --message, and --level (info|success|warn|error).
  • macOS backend: terminal-notifier (if installed)
  • Linux backend: notify-send (if installed)
• scripts/project-notify.sh
  • Derives a project title from PROJECT_PATH basename (preferred), otherwise git root basename, otherwise $PWD basename.
  • Delegates to scripts/desktop-notify.sh.
• LICENSE.txt (Apache 2.0)

Behavior notes

• Default: enabled.
• Missing backend: silent no-op by default (no extra stderr noise).
• Optional install hint: set CODEX_DESKTOP_NOTIFY_HINTS=1 to print a one-line hint to stderr.
• Disable notifications entirely: set CODEX_DESKTOP_NOTIFY=0.
• Unsupported OS: silent no-op.

Usage

Recommended (project-title wrapper):

bash "<path-to-skill>/scripts/project-notify.sh" "Done" --level success

Custom title:

bash "<path-to-skill>/scripts/desktop-notify.sh" --title "my-project" --message "Done" --level info

Testing

• bash -n scripts/desktop-notify.sh scripts/project-notify.sh
• Manual smoke tests:
  • CODEX_DESKTOP_NOTIFY=0 to verify no-op path
  • CODEX_DESKTOP_NOTIFY_HINTS=1 to verify install hint output when backend is missing

Checklist

• I have read the CLA and will sign via the CLA-Assistant PR comment
• Added LICENSE.txt for the new skill
• Scripts default to safe, silent behavior when dependencies are missing
• Documentation includes install hints and environment flags

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[graysurf]

I have read the CLA Document and I hereby sign the CLA